From 68332509ea3e7206620c8cc73fc85955080088a7 Mon Sep 17 00:00:00 2001
From: Stefan Schubert <stefan@bluewhale.de>
Date: Thu, 22 Feb 2024 23:18:13 +0100
Subject: [PATCH] fixes #sabi-113 (#152) (#153)

fixes sabi-113 HTTP.500 after login (returned users)
---
 CHANGELOG.md                                  |  5 ++
 sabi-webclient/pom.xml                        | 40 ++-----------
 .../sabi/webclient/CDIBeans/UserSession.java  | 24 +++++++-
 .../sabi/webclient/config/AppConfig.java      |  2 +-
 .../webclient/config/WebSecurityConfig.java   | 18 ++++--
 .../controller/MeasurementListView.java       |  7 ++-
 .../sabi/webclient/controller/MenuView.java   |  8 ++-
 .../controller/MyErrorController.java         | 45 ++++++++++++++
 .../controller/PasswordForgottenView.java     | 28 ++++-----
 .../sabi/webclient/controller/PlagueView.java |  7 ++-
 .../controller/RegistrationView.java          | 21 ++++---
 .../sabi/webclient/controller/ReportView.java | 11 ++--
 .../webclient/controller/TankListView.java    | 14 ++---
 .../webclient/controller/UserProfileView.java |  9 +--
 .../CustomExceptionHandlerFilter.java         | 59 +++++++++++++++++++
 .../sabi/webclient/utils/PageRegister.java    | 32 ++++++++++
 .../resources/META-INF/resources/login.xhtml  | 39 ++++++------
 .../resources/static/{ => error}/404.html     |  7 ++-
 .../META-INF/resources/static/error/500.html  | 49 +++++++++++++++
 .../resources/static/{ => error}/error.html   | 13 ++--
 .../resources/template/masterLayout.xhtml     | 14 +++--
 .../src/main/resources/application.yml        |  2 +
 .../src/main/resources/log4j2-spring.xml      |  4 +-
 .../src/main/resources/static/error/404.html  | 41 +++++++++++++
 .../src/main/resources/static/error/500.html  | 49 +++++++++++++++
 .../main/resources/static/error/error.html    | 46 +++++++++++++++
 26 files changed, 470 insertions(+), 124 deletions(-)
 create mode 100644 sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/MyErrorController.java
 create mode 100644 sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/security/CustomExceptionHandlerFilter.java
 create mode 100644 sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/utils/PageRegister.java
 rename sabi-webclient/src/main/resources/META-INF/resources/static/{ => error}/404.html (82%)
 create mode 100644 sabi-webclient/src/main/resources/META-INF/resources/static/error/500.html
 rename sabi-webclient/src/main/resources/META-INF/resources/static/{ => error}/error.html (69%)
 create mode 100644 sabi-webclient/src/main/resources/static/error/404.html
 create mode 100644 sabi-webclient/src/main/resources/static/error/500.html
 create mode 100644 sabi-webclient/src/main/resources/static/error/error.html

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6fd25615..7f93c3c9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # History of changes (since 5/2022)
 
+## Release 1.2.5
+
+### Bugfixes
+* HTTP.500 in some cases for returing users with timedout session (sabi-113)
+
 ## Release 1.2.4
 
 ### Bugfixes
diff --git a/sabi-webclient/pom.xml b/sabi-webclient/pom.xml
index 1ba35b51..bc9e1d99 100644
--- a/sabi-webclient/pom.xml
+++ b/sabi-webclient/pom.xml
@@ -10,7 +10,7 @@
 
     <groupId>de.bluewhale</groupId>
     <artifactId>sabi-webclient</artifactId>
-    <version>1.2.4</version>
+    <version>1.2.5</version>
     <packaging>jar</packaging>
     <name>sabi-webclient</name>
     <description>A JSF based webclient for sabi.</description>
@@ -47,7 +47,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>3.1.7</version>
+        <version>3.2.2</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 
@@ -57,8 +57,8 @@
         <java.version>21</java.version>
         <log4j2.version>2.20.0</log4j2.version>
         <jakarta.cdi.version>4.0.1</jakarta.cdi.version>
-        <micrometer.prometheus.version>1.12.2</micrometer.prometheus.version>
-        <joinfaces.version>5.1.4</joinfaces.version>
+        <micrometer.prometheus.version>1.12.3</micrometer.prometheus.version>
+        <joinfaces.version>5.2.2</joinfaces.version>
         <sabi.boundary.version>1.2.5</sabi.boundary.version>
         <passay.version>1.6.4</passay.version>
         <owasp.plugin.version>9.0.9</owasp.plugin.version>
@@ -107,11 +107,6 @@
             </exclusions>
         </dependency>
 
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-validation</artifactId>
-        </dependency>
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-log4j2</artifactId>
@@ -215,22 +210,6 @@
 
     <build>
         <finalName>sabi-webclient</finalName>
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <groupId>org.joinfaces</groupId>
-                    <artifactId>joinfaces-maven-plugin</artifactId>
-                    <version>${joinfaces.version}</version>
-                    <executions>
-                        <execution>
-                            <goals>
-                                <goal>classpath-scan</goal>
-                            </goals>
-                        </execution>
-                    </executions>
-                </plugin>
-            </plugins>
-        </pluginManagement>
 
         <plugins>
             <plugin>
@@ -276,17 +255,6 @@
                 </executions>
             </plugin>
 
-            <plugin>
-                <!--
-                Description from: https://docs.joinfaces.org/current/reference/
-                JoinFaces provides org.joinfaces:joinfaces-maven-plugin Maven plugin
-                to configure a classpath scan at build-time in order to reduce the
-                startup time of applications which use an embedded servlet container.
-                -->
-                <groupId>org.joinfaces</groupId>
-                <artifactId>joinfaces-maven-plugin</artifactId>
-            </plugin>
-
             <plugin>
                 <!-- Used for vulnerability checks
                  The examples below can be executed using mvn verify.
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/CDIBeans/UserSession.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/CDIBeans/UserSession.java
index bded42bb..55ba2b08 100644
--- a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/CDIBeans/UserSession.java
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/CDIBeans/UserSession.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 by Stefan Schubert under the MIT License (MIT).
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
  * See project LICENSE file for the detailed terms and conditions.
  */
 
@@ -8,16 +8,20 @@
 import de.bluewhale.sabi.webclient.utils.I18nUtil;
 import jakarta.annotation.PostConstruct;
 import jakarta.annotation.PreDestroy;
+import jakarta.faces.context.ExternalContext;
 import jakarta.faces.context.FacesContext;
 import jakarta.inject.Inject;
 import jakarta.inject.Named;
+import jakarta.servlet.http.Cookie;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.i18n.LocaleContextHolder;
 import org.springframework.web.context.annotation.SessionScope;
 
 import java.io.Serializable;
+import java.util.Iterator;
 import java.util.Locale;
+import java.util.Map;
 
 /**
  * Container for mandatory things which we need to keep in a user session.
@@ -170,8 +174,24 @@ public void setLanguage(String language) {
 
     /** Invalidates Frontend Session in case of logout. */
     public void endSession(){
+
+        // On the Serverside
         FacesContext context = FacesContext.getCurrentInstance();
-        context.getExternalContext().invalidateSession();
+        ExternalContext externalContext = context.getExternalContext();
+        externalContext.invalidateSession();
+
+        // And on the Client Side. Otherwise the cookies there
+        // might survive and we may observe a HTTP-500
+        // in combination with a server restart, see sabi-113 for details.
+        // Löschen der Cookies
+        Map<String, Object> cookies = externalContext.getRequestCookieMap();
+        Iterator<String> iterator = cookies.keySet().iterator();
+        while (iterator.hasNext()) {
+            String cookieName = iterator.next();
+            Cookie cookie = (Cookie) cookies.get(cookieName);
+            cookie.setMaxAge(0); // By setting the expiration "date" to 0, the cookie is being invalidates by the browser.
+            externalContext.addResponseCookie(cookieName, null, null);
+        }
     }
 
     @PostConstruct
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/config/AppConfig.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/config/AppConfig.java
index 152b45ac..ab3830c4 100644
--- a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/config/AppConfig.java
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/config/AppConfig.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 by Stefan Schubert under the MIT License (MIT).
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
  * See project LICENSE file for the detailed terms and conditions.
  */
 
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/config/WebSecurityConfig.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/config/WebSecurityConfig.java
index 0ca5967f..3bfa4794 100644
--- a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/config/WebSecurityConfig.java
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/config/WebSecurityConfig.java
@@ -1,10 +1,11 @@
 /*
- * Copyright (c) 2023 by Stefan Schubert under the MIT License (MIT).
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
  * See project LICENSE file for the detailed terms and conditions.
  */
 
 package de.bluewhale.sabi.webclient.config;
 
+import de.bluewhale.sabi.webclient.security.CustomExceptionHandlerFilter;
 import de.bluewhale.sabi.webclient.security.SabiDoorKeeper;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Bean;
@@ -12,6 +13,7 @@
 import org.springframework.http.HttpMethod;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.web.SecurityFilterChain;
+import org.springframework.security.web.access.intercept.FilterSecurityInterceptor;
 import org.springframework.security.web.servlet.util.matcher.MvcRequestMatcher;
 import org.springframework.web.servlet.handler.HandlerMappingIntrospector;
 
@@ -31,12 +33,17 @@ public class WebSecurityConfig {
     @Autowired
     SabiDoorKeeper sabiAuthenticationProvider;
 
+    @Autowired
+    private CustomExceptionHandlerFilter customExceptionHandlerFilter;
+
     @Bean
     public SecurityFilterChain filterChain(HttpSecurity http, HandlerMappingIntrospector introspector) throws Exception {
 
         MvcRequestMatcher.Builder mvcMatcherBuilder = new MvcRequestMatcher.Builder(introspector);
         
         http
+                // Add our sabi-113 required exception handler here
+                .addFilterAfter(customExceptionHandlerFilter, FilterSecurityInterceptor.class)
                 .authorizeRequests(authorize -> authorize
                         .requestMatchers(mvcMatcherBuilder.pattern("/jakarta.faces.resource/**")).permitAll()
                         // Allow Pages that don't require an auth context.
@@ -50,8 +57,10 @@ public SecurityFilterChain filterChain(HttpSecurity http, HandlerMappingIntrospe
                         .requestMatchers(mvcMatcherBuilder.pattern( "/logout.xhtml")).permitAll()
                         .requestMatchers(mvcMatcherBuilder.pattern( "/sessionExpired.xhtml")).permitAll()
                         .requestMatchers(mvcMatcherBuilder.pattern( "/credits.xhtml")).permitAll()
-                        .requestMatchers(mvcMatcherBuilder.pattern( "/static/**")).permitAll()
+                        .requestMatchers(mvcMatcherBuilder.pattern( "/static/error/**")).permitAll()
                         .requestMatchers(mvcMatcherBuilder.pattern( "/.well-known/**")).permitAll()
+                        .requestMatchers(mvcMatcherBuilder.pattern( "/error")).permitAll() // Error Controller
+                        .requestMatchers(mvcMatcherBuilder.pattern( "/images/**")).permitAll() // Error Controller
                         // Allow Monitoring Endpoint
                         .requestMatchers(mvcMatcherBuilder.pattern(HttpMethod.GET, "/actuator/**")).permitAll()
                         // all others require authentication
@@ -61,7 +70,7 @@ public SecurityFilterChain filterChain(HttpSecurity http, HandlerMappingIntrospe
 
                 // In Case of a session timeout don't go directly to the login page,
                 // use this page instead, for being able to notify the user what has happened.
-                
+
                 .sessionManagement(session -> session.invalidSessionUrl("/sessionExpired.xhtml"))
 
                 // login - using this the browser redirect to this page if login is required and you are not logged in.
@@ -76,7 +85,8 @@ public SecurityFilterChain filterChain(HttpSecurity http, HandlerMappingIntrospe
                 .authenticationProvider(this.sabiAuthenticationProvider)
 
                 // not needed as JSF 2.2 is implicitly protected against CSRF
-                .csrf(csrf -> csrf.disable());
+                .csrf(csrf -> csrf.disable())
+                ;
 
         return http.build();
     }
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/MeasurementListView.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/MeasurementListView.java
index 98abc673..446b772b 100644
--- a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/MeasurementListView.java
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/MeasurementListView.java
@@ -28,6 +28,8 @@
 import java.util.List;
 import java.util.Locale;
 
+import static de.bluewhale.sabi.webclient.utils.PageRegister.MEASUREMENT_VIEW_PAGE;
+
 /**
  * Controller for the Measurement View as shown in measureView.xhtml
  *
@@ -39,7 +41,6 @@
 @Getter
 public class MeasurementListView extends AbstractControllerTools implements Serializable  {
 
-    private static final String MEASUREMENT_VIEW_PAGE = "measureView";
     private static final int MAX_RESULT_COUNT = 5;
 
     @Autowired
@@ -119,7 +120,7 @@ public String getTankNameForId(Long tankId) {
 
     public String resetForm() {
         measurement = new MeasurementTo();
-        return MEASUREMENT_VIEW_PAGE;
+        return MEASUREMENT_VIEW_PAGE.getNavigationableAddress();
     }
 
     public String save() {
@@ -135,7 +136,7 @@ public String save() {
         } else {
             MessageUtil.warn("troubleMsg", "common.incompleted_formdata.t", userSession.getLocale());
         }
-        return MEASUREMENT_VIEW_PAGE;
+        return MEASUREMENT_VIEW_PAGE.getNavigationableAddress();
     }
 
     private boolean allDataProvided(MeasurementTo measurement) {
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/MenuView.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/MenuView.java
index 8d35bf32..c62c9335 100644
--- a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/MenuView.java
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/MenuView.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 by Stefan Schubert under the MIT License (MIT).
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
  * See project LICENSE file for the detailed terms and conditions.
  */
 
@@ -9,6 +9,8 @@
 import jakarta.inject.Named;
 import lombok.extern.slf4j.Slf4j;
 
+import static de.bluewhale.sabi.webclient.utils.PageRegister.LOGOUT_PAGE;
+
 /**
  * MenuActions
  *
@@ -19,7 +21,7 @@
 @Slf4j
 public class MenuView {
 
-    static String LOGOUT_PAGE = "/logout?faces-redirect=true";
+    // static String LOGOUT_PAGE = "/logout?faces-redirect=true";
 
     /**
      * Kills the sessions. The frontend session will be invalidated during rendering
@@ -30,7 +32,7 @@ public class MenuView {
      */
     public String logout() {
         log.info(" #### User logged out. ####");
-        return LOGOUT_PAGE;
+        return "/"+LOGOUT_PAGE.getNavigationableAddress()+"?faces-redirect=true";
     }
 
 }
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/MyErrorController.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/MyErrorController.java
new file mode 100644
index 00000000..5a281fb3
--- /dev/null
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/MyErrorController.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
+ * See project LICENSE file for the detailed terms and conditions.
+ */
+
+package de.bluewhale.sabi.webclient.controller;
+
+import jakarta.servlet.RequestDispatcher;
+import jakarta.servlet.http.HttpServletRequest;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.boot.web.servlet.error.ErrorController;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.RequestMapping;
+
+/**
+ * Nice try (to solve sabi-113) but It won't work for <b>jakarta.faces.application.ViewExpiredException</b>
+ * as the Controller will be involved in the Context of the DispatcherServlet, which won't happen for errors
+ * occurring in the JSF engine. The error which has been seen by sabi-113 us happening
+ * in the Context of the FacesServlet which gets uncaught all way up through the springframework.security.eb Filterchain.
+ * <p>
+ * So though this Error-Controller configuration is more or less dead code because of the
+ * Faces Techstack here, I will leave it with this explanation as reference in it.
+ */
+@Controller
+@Slf4j
+public class MyErrorController implements ErrorController {
+
+    @RequestMapping("/error")
+    public String handleError(HttpServletRequest request) {
+        Object status = request.getAttribute(RequestDispatcher.ERROR_STATUS_CODE);
+
+        if (status != null) {
+            Integer statusCode = Integer.valueOf(status.toString());
+
+            if (statusCode == HttpStatus.NOT_FOUND.value()) {
+                return "/static/error/404.html";
+            } else if (statusCode == HttpStatus.INTERNAL_SERVER_ERROR.value()) {
+                return "/static/error/500.html";
+            }
+        }
+
+        return "/static/error/error.html"; // fallback
+    }
+}
\ No newline at end of file
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/PasswordForgottenView.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/PasswordForgottenView.java
index 90e3efb8..507dc583 100644
--- a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/PasswordForgottenView.java
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/PasswordForgottenView.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 by Stefan Schubert under the MIT License (MIT).
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
  * See project LICENSE file for the detailed terms and conditions.
  */
 
@@ -12,6 +12,7 @@
 import de.bluewhale.sabi.webclient.CDIBeans.UserSession;
 import de.bluewhale.sabi.webclient.model.ChallengeTo;
 import de.bluewhale.sabi.webclient.utils.MessageUtil;
+import de.bluewhale.sabi.webclient.utils.PageRegister;
 import de.bluewhale.sabi.webclient.utils.PasswordPolicy;
 import de.bluewhale.sabi.webclient.utils.RestHelper;
 import jakarta.inject.Named;
@@ -32,6 +33,8 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import static de.bluewhale.sabi.webclient.utils.PageRegister.PASSWORD_FORGOTTEN_PAGE;
+
 
 /**
  * Manages password forgotten use case
@@ -43,9 +46,6 @@
 @Slf4j
 public class PasswordForgottenView implements Serializable {
 
-    static String PASSWORD_FORGOTTEN_PAGE = "pwreset";
-    static String LOGIN_PAGE = "login";
-
     @Value("${captcha.backend.url}")
     private String captchaBackendUrl;
 
@@ -117,7 +117,7 @@ public String resetPassword() {
         // preliminary checks
         if (PasswordPolicy.failedCheck(pwResetModel.getNewPassword(), checkPwd)) {
             MessageUtil.error("messages5", "register.password.policy_failed.t", userSession.getLocale());
-            return PASSWORD_FORGOTTEN_PAGE;
+            return PASSWORD_FORGOTTEN_PAGE.getNavigationableAddress();
         }
 
         // Continue processing by calling the backend
@@ -129,7 +129,7 @@ public String resetPassword() {
         } catch (JsonProcessingException e) {
             log.error("Couldn't convert form data into JSON reprasentation. {}", e);
             MessageUtil.fatal("commonerror", "common.error.backend_unreachable.l", userSession.getLocale());
-            return PASSWORD_FORGOTTEN_PAGE;
+            return PASSWORD_FORGOTTEN_PAGE.getNavigationableAddress();
         }
 
         HttpEntity<String> entity = new HttpEntity<String>(requestJson, headers);
@@ -153,7 +153,7 @@ public String resetPassword() {
             MessageUtil.fatal("commonerror", "common.error.backend_unreachable.l", userSession.getLocale());
         }
 
-        return PASSWORD_FORGOTTEN_PAGE;
+        return PASSWORD_FORGOTTEN_PAGE.getNavigationableAddress();
     }
 
     /**
@@ -164,7 +164,7 @@ public String resetWorkflow() {
         pwResetted = false;
         pwReqModel = new RequestNewPasswordTo();
         pwResetModel = new ResetPasswordTo();
-        return LOGIN_PAGE;
+        return PageRegister.LOGIN_PAGE.getNavigationableAddress();
     }
 
     /**
@@ -180,7 +180,7 @@ public String reqPasswordResetMail() {
         String userAnswer = pwReqModel.getCaptchaToken();
         if (Strings.isEmpty(userAnswer)) {
             MessageUtil.error("captcha", "register.captcha_missing.t", userSession.getLocale());
-            return PASSWORD_FORGOTTEN_PAGE;
+            return PASSWORD_FORGOTTEN_PAGE.getNavigationableAddress();
         }
 
         // Continue processing by calling the backend
@@ -192,7 +192,7 @@ public String reqPasswordResetMail() {
         } catch (JsonProcessingException e) {
             log.error("Coudn't convert form data into JSON reprasentation. {}", e);
             MessageUtil.fatal("commonerror", "common.error.backend_unreachable.l", userSession.getLocale());
-            return PASSWORD_FORGOTTEN_PAGE;
+            return PASSWORD_FORGOTTEN_PAGE.getNavigationableAddress();
         }
 
         HttpEntity<String> entity = new HttpEntity<String>(requestJson, headers);
@@ -203,7 +203,7 @@ public String reqPasswordResetMail() {
             if (HttpStatus.ACCEPTED.equals(responseEntity.getStatusCode())) {
                 captchaAccepted = true; // signals to proceed with the form.
                 MessageUtil.info("captcha", "pw_forgotten.reset_request_accepted.t", userSession.getLocale());
-                return PASSWORD_FORGOTTEN_PAGE;
+                return PASSWORD_FORGOTTEN_PAGE.getNavigationableAddress();
             }
 
         } catch (HttpClientErrorException e) {
@@ -217,16 +217,16 @@ public String reqPasswordResetMail() {
 
             }
             fetchNewCaptchaChallenge();
-            return PASSWORD_FORGOTTEN_PAGE;
+            return PASSWORD_FORGOTTEN_PAGE.getNavigationableAddress();
 
         } catch (RestClientException e) {
             log.error("Backend processing error. {}", e);
             MessageUtil.fatal("commonerror", "common.error.backend_unreachable.l", userSession.getLocale());
-            return PASSWORD_FORGOTTEN_PAGE;
+            return PASSWORD_FORGOTTEN_PAGE.getNavigationableAddress();
         }
 
         // any unhandled case? stays on the same page!
-        return PASSWORD_FORGOTTEN_PAGE;
+        return PASSWORD_FORGOTTEN_PAGE.getNavigationableAddress();
     }
 
     /**
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/PlagueView.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/PlagueView.java
index 98af5ae0..cc2ae438 100644
--- a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/PlagueView.java
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/PlagueView.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 by Stefan Schubert under the MIT License (MIT).
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
  * See project LICENSE file for the detailed terms and conditions.
  */
 
@@ -32,6 +32,8 @@
 import java.util.*;
 import java.util.stream.Collectors;
 
+import static de.bluewhale.sabi.webclient.utils.PageRegister.PLAGUE_VIEW_PAGE;
+
 /**
  * Controller for the plague center as shown in plagueView.xhtml
  *
@@ -44,7 +46,6 @@
 @Setter
 public class PlagueView extends AbstractControllerTools implements Serializable {
 
-    private static final String PLAGUE_VIEW_PAGE = "plagueView";
     private static final Integer PLAGUE_CURED_STATUS_ID = 5; // Needs to match vanished state in table localized_plague_status.
 
     @Autowired
@@ -300,7 +301,7 @@ public String save() {
         } else {
             MessageUtil.warn("saveresult", "common.incompleted_formdata.t", userSession.getLocale());
         }
-        return PLAGUE_VIEW_PAGE;
+        return PLAGUE_VIEW_PAGE.getNavigationableAddress();
     }
 
     private boolean allDataProvided(PlagueRecordTo plagueRecordTo) {
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/RegistrationView.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/RegistrationView.java
index 927baea3..233fbc57 100644
--- a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/RegistrationView.java
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/RegistrationView.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 by Stefan Schubert under the MIT License (MIT).
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
  * See project LICENSE file for the detailed terms and conditions.
  */
 
@@ -34,6 +34,8 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import static de.bluewhale.sabi.webclient.utils.PageRegister.PREREGISTER_PAGE;
+import static de.bluewhale.sabi.webclient.utils.PageRegister.REGISTER_PAGE;
 
 
 /**
@@ -47,9 +49,6 @@
 public class RegistrationView implements Serializable {
 // ------------------------------ FIELDS ------------------------------
 
-    static String REGISTER_PAGE = "register";
-    static String PREREGISTER_PAGE = "preregistration";
-
     @Value("${captcha.backend.url}")
     private String captchaBackendUrl;
 
@@ -104,12 +103,12 @@ public String doRegister() {
         String userAnswer = model.getCaptchaCode();
         if (Strings.isEmpty(userAnswer)) {
             MessageUtil.error("captcha", "register.captcha_missing.t", userSession.getLocale());
-            return REGISTER_PAGE;
+            return REGISTER_PAGE.getNavigationableAddress();
         }
 
         if (PasswordPolicy.failedCheck(model.getPassword(), checkPwd)) {
             MessageUtil.error("pwd2", "register.password.policy_failed.t", userSession.getLocale());
-            return REGISTER_PAGE;
+            return REGISTER_PAGE.getNavigationableAddress();
         }
 
         // For registration, we take the language settings from guessed environment
@@ -126,7 +125,7 @@ public String doRegister() {
             log.error("Couldn't convert form data into JSON representation. {}", e);
             String message = MessageUtil.getFromMessageProperties("common.error.backend_unreachable.l", userSession.getLocale());
             MessageUtil.fatal("captcha", message);
-            return REGISTER_PAGE;
+            return REGISTER_PAGE.getNavigationableAddress();
         }
 
         HttpEntity<String> entity = new HttpEntity<String>(requestJson, headers);
@@ -136,7 +135,7 @@ public String doRegister() {
             ResponseEntity<UserTo> responseEntity = restTemplate.postForEntity(registerURI, entity, UserTo.class);
 
             if (HttpStatus.CREATED.equals(responseEntity.getStatusCode())) {
-                return PREREGISTER_PAGE;
+                return PREREGISTER_PAGE.getNavigationableAddress();
             }
 
         } catch (HttpClientErrorException e) {
@@ -153,16 +152,16 @@ public String doRegister() {
 
             }
             fetchNewCaptchaChallenge();
-            return REGISTER_PAGE;
+            return REGISTER_PAGE.getNavigationableAddress();
         } catch (RestClientException e) {
             log.error("Backend processing error. {}", e);
             String message = MessageUtil.getFromMessageProperties("common.error.backend_unreachable.l", userSession.getLocale());
             MessageUtil.fatal("commonFailure", message);
-            return REGISTER_PAGE;
+            return REGISTER_PAGE.getNavigationableAddress();
         }
 
         // any unhandled case? stays on the same page!
-        return REGISTER_PAGE;
+        return REGISTER_PAGE.getNavigationableAddress();
     }
 
 
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/ReportView.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/ReportView.java
index 9555c442..881e70db 100644
--- a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/ReportView.java
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/ReportView.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 by Stefan Schubert under the MIT License (MIT).
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
  * See project LICENSE file for the detailed terms and conditions.
  */
 
@@ -38,6 +38,8 @@
 import java.util.*;
 import java.util.stream.Collectors;
 
+import static de.bluewhale.sabi.webclient.utils.PageRegister.REPORT_VIEW_PAGE;
+
 /**
  * Controller for the Report View as shown in reportView.xhtml
  *
@@ -52,7 +54,6 @@ public class ReportView extends AbstractControllerTools implements Serializable
 
     // Limit drawn graph to avoid steady visual narrowing of target range by global minimum or maximum measurements
     final static int MAX_GRAPH_RECORDS = 14;
-    private static final String REPORT_VIEW_PAGE = "reportView";
     @Autowired
     TankService tankService;
 
@@ -85,14 +86,14 @@ public String requestData() {
 
         if (selectedTankId == null || selectedUnitId == null) {
             MessageUtil.info("messages", "common.no_such_data.t", userSession.getLocale());
-            return REPORT_VIEW_PAGE;
+            return REPORT_VIEW_PAGE.getNavigationableAddress();
         }
 
         try {
             measurementTos = measurementService.getMeasurementsForUsersTankFilteredByUnit(userSession.getSabiBackendToken(), selectedTankId, selectedUnitId);
 
             if (measurementTos == null || measurementTos.isEmpty()) {
-                return REPORT_VIEW_PAGE;
+                return REPORT_VIEW_PAGE.getNavigationableAddress();
             }
 
             // Ensure that measured points are sorted
@@ -220,7 +221,7 @@ public String requestData() {
             e.printStackTrace();
         }
 
-        return REPORT_VIEW_PAGE;
+        return REPORT_VIEW_PAGE.getNavigationableAddress();
     }
 
     private void populteDataSet(LineChartDataSet lineChartDataSet, List<Object> valuesList, List<String> labelsList, LineChartModel lineChartModel, boolean spanGAPs) {
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/TankListView.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/TankListView.java
index da53be5e..2eae401a 100644
--- a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/TankListView.java
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/TankListView.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023 by Stefan Schubert under the MIT License (MIT).
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
  * See project LICENSE file for the detailed terms and conditions.
  */
 
@@ -26,6 +26,9 @@
 import java.util.List;
 import java.util.Map;
 
+import static de.bluewhale.sabi.webclient.utils.PageRegister.TANK_EDITOR_PAGE;
+import static de.bluewhale.sabi.webclient.utils.PageRegister.TANK_VIEW_PAGE;
+
 /**
  * Controller for the Tanklist View as shown in tankView.xhtml
  *
@@ -37,9 +40,6 @@
 @Getter
 public class TankListView implements Serializable {
 
-    private static final String TANK_EDITOR_PAGE = "tankEditor";
-    private static final String TANK_VIEW_PAGE = "tankView";
-
     @Autowired
     TankService tankService;
 
@@ -77,12 +77,12 @@ public void endOfService() {
 
     public String edit(AquariumTo tank) {
         selectedTank = tank;
-        return TANK_EDITOR_PAGE;
+        return TANK_EDITOR_PAGE.getNavigationableAddress();
     }
 
     public String addTank() {
         selectedTank = new AquariumTo();
-        return TANK_EDITOR_PAGE;
+        return TANK_EDITOR_PAGE.getNavigationableAddress();
     }
 
     public void delete(AquariumTo tank) {
@@ -120,7 +120,7 @@ public String save() {
                 MessageUtil.warn("messages","common.error.internal_server_problem.t",userSession.getLocale());
             }
         }
-        return TANK_VIEW_PAGE;
+        return TANK_VIEW_PAGE.getNavigationableAddress();
     }
 
 }
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/UserProfileView.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/UserProfileView.java
index 5015de2e..df00546f 100644
--- a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/UserProfileView.java
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/controller/UserProfileView.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 by Stefan Schubert under the MIT License (MIT).
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
  * See project LICENSE file for the detailed terms and conditions.
  */
 
@@ -27,6 +27,8 @@
 import java.time.LocalDateTime;
 import java.util.*;
 
+import static de.bluewhale.sabi.webclient.utils.PageRegister.USER_PROFILE_VIEW_PAGE;
+
 /**
  * Controller for the Report View as shown in reportView.xhtml
  *
@@ -38,7 +40,6 @@
 @Data
 public class UserProfileView extends AbstractControllerTools implements Serializable {
 
-    private static final String USER_PROFILE_VIEW_PAGE = "userProfile";
     private static final int DEFAULT_MEASUREMENT_INTERVAL_IN_DAYS = 7;
 
     @Inject
@@ -96,7 +97,7 @@ public String save() {
                 MessageUtil.warn("profileupdate", "common.error.internal_server_problem.t", userSession.getLocale());
             }
         }
-        return USER_PROFILE_VIEW_PAGE;
+        return USER_PROFILE_VIEW_PAGE.getNavigationableAddress();
     }
 
     public String addReminderForMeasurementUnit() {
@@ -121,7 +122,7 @@ public String addReminderForMeasurementUnit() {
             }
 
         }
-        return USER_PROFILE_VIEW_PAGE;
+        return USER_PROFILE_VIEW_PAGE.getNavigationableAddress();
     }
 
 
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/security/CustomExceptionHandlerFilter.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/security/CustomExceptionHandlerFilter.java
new file mode 100644
index 00000000..42e95ec8
--- /dev/null
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/security/CustomExceptionHandlerFilter.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
+ * See project LICENSE file for the detailed terms and conditions.
+ */
+
+package de.bluewhale.sabi.webclient.security;
+
+import jakarta.servlet.FilterChain;
+import jakarta.servlet.RequestDispatcher;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Component;
+import org.springframework.web.filter.OncePerRequestFilter;
+
+import java.io.IOException;
+
+/**
+ * Because of our SpringSecurity config the standard spring exception handler conventional configuration
+ * nor the ExceptionHandler Extensions which are based upon the Dispatcher Servlet, does
+ * not work here because of the FacesServlet context.
+ *
+ * As a workaround we use a Filter we will add to the security filter chain instead.
+ */
+@Component
+@Slf4j
+public class CustomExceptionHandlerFilter extends OncePerRequestFilter {
+
+    @Override
+    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
+            throws ServletException, IOException {
+        try {
+            Object status = request.getAttribute(RequestDispatcher.ERROR_STATUS_CODE);
+
+            if (log.isDebugEnabled()) {
+                String requestStatus = (status != null) ? status.toString() : "Null";
+                log.debug("Passing Custom Exception Filter with request status {}",requestStatus);
+            }
+
+            if (status != null) {
+                HttpStatus httpStatus = HttpStatus.valueOf(status.toString());
+                log.warn("There was a servlet problem. Returned httpStatus {}",httpStatus);
+                switch (httpStatus) {
+                    case HttpStatus.NOT_FOUND -> response.sendRedirect("/error");
+                    case HttpStatus.INTERNAL_SERVER_ERROR -> response.sendRedirect("/error");
+                }
+
+            }
+
+            filterChain.doFilter(request, response);
+        } catch (Exception e) {
+            // Any error within the filter? Call the error Controller.
+            log.error("Exception Filter could not access request due to previous error rerouting to error controller.",e);
+            response.sendRedirect("/error");
+        }
+    }
+}
\ No newline at end of file
diff --git a/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/utils/PageRegister.java b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/utils/PageRegister.java
new file mode 100644
index 00000000..df3b5e9e
--- /dev/null
+++ b/sabi-webclient/src/main/java/de/bluewhale/sabi/webclient/utils/PageRegister.java
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
+ * See project LICENSE file for the detailed terms and conditions.
+ */
+
+package de.bluewhale.sabi.webclient.utils;
+
+// One place to resolve page names for navigational issues.
+public enum PageRegister {
+
+    LOGIN_PAGE("login"),
+    LOGOUT_PAGE("logout"),
+    PLAGUE_VIEW_PAGE("plagueView"),
+    REGISTER_PAGE("register"),
+    PREREGISTER_PAGE("preregistration"),
+    REPORT_VIEW_PAGE("reportView"),
+    TANK_EDITOR_PAGE("tankEditor"),
+    TANK_VIEW_PAGE("tankView"),
+    MEASUREMENT_VIEW_PAGE("measureView"),
+    USER_PROFILE_VIEW_PAGE("userProfile"),
+    PASSWORD_FORGOTTEN_PAGE ("pwreset");
+
+    String address;
+
+    PageRegister(String pageAddress) {
+        this.address = pageAddress;
+    }
+
+    public String getNavigationableAddress() {
+        return address;
+    }
+}
diff --git a/sabi-webclient/src/main/resources/META-INF/resources/login.xhtml b/sabi-webclient/src/main/resources/META-INF/resources/login.xhtml
index afb9318e..664f6f8b 100644
--- a/sabi-webclient/src/main/resources/META-INF/resources/login.xhtml
+++ b/sabi-webclient/src/main/resources/META-INF/resources/login.xhtml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
-  - Copyright (c) 2023 by Stefan Schubert under the MIT License (MIT).
+  - Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
   - See project LICENSE file for the detailed terms and conditions.
   -->
 
@@ -13,7 +13,10 @@
       xmlns:f="http://xmlns.jcp.org/jsf/core">
 
 <f:metadata>
-    <f:view locale="#{userSession.locale}" language="#{userSession.language}" contentType="text/html" encoding="utf-8"/>
+    <f:view locale="#{userSession.locale}"
+            language="#{userSession.language}"
+            contentType="text/html"
+            encoding="utf-8"/>
     <f:loadBundle basename="i18n.messages" var="msg"/>
     <!-- Workaround (for broken workflow) -->
     <f:viewAction action="#{passwordForgottenView.resetWorkflow}"/>
@@ -33,7 +36,7 @@
 
 <h:body styleClass="splashscreen">
     <ui:remove>
-    <!--
+        <!--
     We specify prependId="false" on the form as otherwise the JSF framework will prefix the parameters with the ID of the form.
     but we require username and password inputfields unchanges, as spring-security will look them up.
 
@@ -44,28 +47,28 @@
     <div style="height:50vh"/>
     <h:form id="login-form" prependId="false">
 
-        <p:panel header="#{msg['login.welcome.h']} (#{applicationInfo.version})">
-            <h3>#{msg['login.panel.h']}</h3>
-            <p:panelGrid columns="2" styleClass="ui-fluid center ui-noborder">
+            <p:panel header="#{msg['login.welcome.h']} (#{applicationInfo.version})">
+                <h3>#{msg['login.panel.h']}</h3>
+                <p:panelGrid columns="2" styleClass="ui-fluid center ui-noborder">
 
-                <p:outputLabel value="#{msg['login.username.l']}" for="username"/>
-                <p:inputText id="username" placeholder="username or email"/>
+                    <p:outputLabel value="#{msg['login.username.l']}" for="username"/>
+                    <p:inputText id="username" placeholder="username or email"/>
 
-                <p:outputLabel value="#{msg['login.password.l']}" for="password"/>
-                <p:password id="password" placeholder="password"/>
+                    <p:outputLabel value="#{msg['login.password.l']}" for="password"/>
+                    <p:password id="password" placeholder="password"/>
 
-                <p:commandButton ajax="false" value="Login"/>
-                <p:link outcome="pwreset" value="#{msg['login.resetPW.b']}"/>
+                    <p:commandButton ajax="false" value="Login"/>
+                    <p:link outcome="pwreset" value="#{msg['login.resetPW.b']}"/>
 
-                <p:outputLabel value="#{msg['login.register.l']}" for="reglink"/>
-                <p:link id="reglink" outcome="register" value="#{msg['welcome.but.register']}"/>
+                    <p:outputLabel value="#{msg['login.register.l']}" for="reglink"/>
+                    <p:link id="reglink" outcome="register" value="#{msg['welcome.but.register']}"/>
 
-            </p:panelGrid>
+                </p:panelGrid>
 
-            <p:outputLabel value="#{msg['login.forgottenPW.l']}" style="font-style: oblique; color: red"
-                           rendered="${!empty param['error']}"/>
+                <p:outputLabel value="#{msg['login.forgottenPW.l']}" style="font-style: oblique; color: red"
+                               rendered="${!empty param['error']}"/>
 
-        </p:panel>
+            </p:panel>
 
     </h:form>
 
diff --git a/sabi-webclient/src/main/resources/META-INF/resources/static/404.html b/sabi-webclient/src/main/resources/META-INF/resources/static/error/404.html
similarity index 82%
rename from sabi-webclient/src/main/resources/META-INF/resources/static/404.html
rename to sabi-webclient/src/main/resources/META-INF/resources/static/error/404.html
index 9cd4d6ba..f8d5fd2f 100644
--- a/sabi-webclient/src/main/resources/META-INF/resources/static/404.html
+++ b/sabi-webclient/src/main/resources/META-INF/resources/static/error/404.html
@@ -1,5 +1,5 @@
 <!--
-  ~ Copyright (c) 2021 by Stefan Schubert under the MIT License (MIT).
+  ~ Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
   ~ See project LICENSE file for the detailed terms and conditions.
   -->
 
@@ -7,14 +7,15 @@
 <html>
 <head>
     <title>Ups..</title>
+    <meta name="robots" content="none" />
 </head>
 <body>
 <h1>Ups...404 file not found</h1>
 
 
-<table cellpadding="5px">
+<table>
     <tr>
-        <td><img src="../images/Clibanarius.JPG" alt="Clibanarius" align="center"/></td>
+        <td><img src="/images/Clibanarius.JPG" alt="Clibanarius crap" width="280" height="200"/></td>
         <td>
             <p>
                 Do we have a broken file link?
diff --git a/sabi-webclient/src/main/resources/META-INF/resources/static/error/500.html b/sabi-webclient/src/main/resources/META-INF/resources/static/error/500.html
new file mode 100644
index 00000000..5179fc2a
--- /dev/null
+++ b/sabi-webclient/src/main/resources/META-INF/resources/static/error/500.html
@@ -0,0 +1,49 @@
+<!--
+  ~ Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
+  ~ See project LICENSE file for the detailed terms and conditions.
+  -->
+
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Ups..</title>
+    <meta name="robots" content="none" />
+</head>
+<body>
+<h1>Ups...500 internal error</h1>
+
+
+<table>
+    <tr>
+        <td><img src="/images/Clibanarius.JPG" alt="Clibanarius crap" width="280" height="200"/></td>
+        <td>
+            <p>
+                Sorry, there was an unplanned error.
+            </p>
+            <p>
+            Currently there is one known issue with returning users
+            which was raised already <a href="https://github.com/StefanSchubert/sabi/issues/113">here.</a>
+            This is currently caused with a broken client side view state due to a server redeployment.
+                </p>
+            <p>Unfortunate this problem has nit been solved yet.
+            The workaround is to re-login by going into browsers URL field and remove everything after the last "/" and hit enter again.
+            </p>
+
+            <p>
+                Just in case the problem has not been solved by the workaround:</b>
+                YOU can still help! If you can reproduce the error please submit a trouble ticket with detail description what happened
+                and led to the problem at: projects <a href="https://github.com/StefanSchubert/sabi/issues">Issues</a>
+                tracker.<br/>
+                Before open an own ticket, have a look if some other already reported a problem and leave a comment
+                there instead.
+            </p>
+            <p>
+                Thanks for supporting the project and sorry for any inconvenience caused.
+            </p>
+        </td>
+    </tr>
+</table>
+
+
+</body>
+</html>
\ No newline at end of file
diff --git a/sabi-webclient/src/main/resources/META-INF/resources/static/error.html b/sabi-webclient/src/main/resources/META-INF/resources/static/error/error.html
similarity index 69%
rename from sabi-webclient/src/main/resources/META-INF/resources/static/error.html
rename to sabi-webclient/src/main/resources/META-INF/resources/static/error/error.html
index dd79e5ae..bd474116 100644
--- a/sabi-webclient/src/main/resources/META-INF/resources/static/error.html
+++ b/sabi-webclient/src/main/resources/META-INF/resources/static/error/error.html
@@ -1,5 +1,5 @@
 <!--
-  ~ Copyright (c) 2021 by Stefan Schubert under the MIT License (MIT).
+  ~ Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
   ~ See project LICENSE file for the detailed terms and conditions.
   -->
 
@@ -7,18 +7,22 @@
 <html>
 <head>
     <title>Ups..</title>
+    <meta name="robots" content="none" />
 </head>
 <body>
-<h1>Ups...something went wrong with Sabis Frontend</h1>
+<h1>Ups...something went wrong with Sabis' Frontend</h1>
 
 
-<table cellpadding="5px">
+<table>
     <tr>
-        <td><img src="../images/Clibanarius.JPG" alt="Clibanarius" align="center"/></td>
+        <td><img src="/images/Clibanarius.JPG" alt="Clibanarius crap" width="280" height="200"/></td>
         <td>
             <p>
                 Sorry for that, but no reason to worry ;-)<br/>
+                <br/>
                 Some exception in the frontend logic occurred I probably haven't considered yet.
+                Please try again: <a href="/">https://sabi-project.net/</a> and if that doesn't fix it
+                consider the suggested feedback in the next paragraph.
             </p>
 
             <p>
@@ -29,6 +33,7 @@ <h1>Ups...something went wrong with Sabis Frontend</h1>
                 Before open an own ticket, have a look if some other already reported a problem and leave a comment
                 there instead.
             </p>
+
             <p>
                 Thanks for supporting the project and sorry for any inconvenience caused.
             </p>
diff --git a/sabi-webclient/src/main/resources/META-INF/resources/template/masterLayout.xhtml b/sabi-webclient/src/main/resources/META-INF/resources/template/masterLayout.xhtml
index f3abcb22..bf1f1d02 100644
--- a/sabi-webclient/src/main/resources/META-INF/resources/template/masterLayout.xhtml
+++ b/sabi-webclient/src/main/resources/META-INF/resources/template/masterLayout.xhtml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
-  - Copyright (c) 2023 by Stefan Schubert under the MIT License (MIT).
+  - Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
   - See project LICENSE file for the detailed terms and conditions.
   -->
 
@@ -30,9 +30,15 @@
 
 <h:body styleClass="baselayout">
 
-    <div id="header"><ui:include src="/template/header.xhtml"/></div>
-    <div id="content"><ui:insert name="content">Sorry content is missing. Report to site owner.</ui:insert></div>
-    <div id="footer"><ui:include src="/template/footer.xhtml"/></div>
+    <div id="header">
+        <ui:include src="/template/header.xhtml"/>
+    </div>
+    <div id="content">
+        <ui:insert name="content">Sorry content is missing. Report to site owner.</ui:insert>
+    </div>
+    <div id="footer">
+        <ui:include src="/template/footer.xhtml"/>
+    </div>
 
 </h:body>
 </html>
\ No newline at end of file
diff --git a/sabi-webclient/src/main/resources/application.yml b/sabi-webclient/src/main/resources/application.yml
index ef2a7d02..ad56b5de 100644
--- a/sabi-webclient/src/main/resources/application.yml
+++ b/sabi-webclient/src/main/resources/application.yml
@@ -41,6 +41,8 @@ server:
   error:
     whitelabel:
       enabled: false
+    # This will cause error occuring in DsipatcherServlet Context to be routed through the Controller listening on the /error Endpoint
+    path: /error
   servlet:
     session:
       # dev. setting for sessionExpired
diff --git a/sabi-webclient/src/main/resources/log4j2-spring.xml b/sabi-webclient/src/main/resources/log4j2-spring.xml
index 6c9e1f39..fef89177 100644
--- a/sabi-webclient/src/main/resources/log4j2-spring.xml
+++ b/sabi-webclient/src/main/resources/log4j2-spring.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <!--
-  ~ Copyright (c) 2023 by Stefan Schubert under the MIT License (MIT).
+  ~ Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
   ~ See project LICENSE file for the detailed terms and conditions.
   -->
 
@@ -36,7 +36,7 @@
             <AppenderRef ref="RollingFile" />
         </Root>
 
-        <Logger name="de.bluewhale.sabi" level="INFO"/>
+        <Logger name="de.bluewhale.sabi" level="DEBUG"/>
     </Loggers>
 
 </Configuration>
\ No newline at end of file
diff --git a/sabi-webclient/src/main/resources/static/error/404.html b/sabi-webclient/src/main/resources/static/error/404.html
new file mode 100644
index 00000000..d4e6b5f7
--- /dev/null
+++ b/sabi-webclient/src/main/resources/static/error/404.html
@@ -0,0 +1,41 @@
+<!--
+  ~ Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
+  ~ See project LICENSE file for the detailed terms and conditions.
+  -->
+
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Ups..🙈</title>
+    <meta name="robots" content="none" />
+</head>
+<body>
+<h1>Ups...404 file not found</h1>
+
+
+<table>
+    <tr>
+        <td><img src="/images/Clibanarius.JPG" alt="Clibanarius crap" width="280" height="200"/></td>
+        <td>
+            <p>
+                Do we have a broken file link?
+            </p>
+
+            <p>
+                Good news is: YOU can help! First wait a while and try again.
+                If you can reproduce the error please submit a trouble ticket with detail description what happened
+                and led to the problem at: projects <a href="https://github.com/StefanSchubert/sabi/issues">Issues</a>
+                tracker.<br/>
+                Before open an own ticket, have a look if some other already reported a problem and leave a comment
+                there instead.
+            </p>
+            <p>
+                Thanks for supporting the project and sorry for any inconvenience caused.
+            </p>
+        </td>
+    </tr>
+</table>
+
+
+</body>
+</html>
\ No newline at end of file
diff --git a/sabi-webclient/src/main/resources/static/error/500.html b/sabi-webclient/src/main/resources/static/error/500.html
new file mode 100644
index 00000000..21c5f936
--- /dev/null
+++ b/sabi-webclient/src/main/resources/static/error/500.html
@@ -0,0 +1,49 @@
+<!--
+  ~ Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
+  ~ See project LICENSE file for the detailed terms and conditions.
+  -->
+
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Ups..🙈</title>
+    <meta name="robots" content="none" />
+</head>
+<body>
+<h1>Ups...500 internal error</h1>
+
+
+<table>
+    <tr>
+        <td><img src="/images/Clibanarius.JPG" alt="Clibanarius crap" width="280" height="200"/></td>
+        <td>
+            <p>
+                Sorry, there was an unplanned error.
+            </p>
+            <p>
+            Currently there is one known issue with returning users
+            which was raised already <a href="https://github.com/StefanSchubert/sabi/issues/113">here.</a>
+            This is currently caused with a broken client side view state due to a server redeployment.
+                </p>
+            <p>Unfortunate this problem has nit been solved yet.
+            The workaround is to re-login by going into browsers URL field and remove everything after the last "/" and hit enter again.
+            </p>
+
+            <p>
+                Just in case the problem has not been solved by the workaround:</b>
+                YOU can still help! If you can reproduce the error please submit a trouble ticket with detail description what happened
+                and led to the problem at: projects <a href="https://github.com/StefanSchubert/sabi/issues">Issues</a>
+                tracker.<br/>
+                Before open an own ticket, have a look if some other already reported a problem and leave a comment
+                there instead.
+            </p>
+            <p>
+                Thanks for supporting the project and sorry for any inconvenience caused.
+            </p>
+        </td>
+    </tr>
+</table>
+
+
+</body>
+</html>
\ No newline at end of file
diff --git a/sabi-webclient/src/main/resources/static/error/error.html b/sabi-webclient/src/main/resources/static/error/error.html
new file mode 100644
index 00000000..f98b77c2
--- /dev/null
+++ b/sabi-webclient/src/main/resources/static/error/error.html
@@ -0,0 +1,46 @@
+<!--
+  ~ Copyright (c) 2024 by Stefan Schubert under the MIT License (MIT).
+  ~ See project LICENSE file for the detailed terms and conditions.
+  -->
+
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Ups..🙈</title>
+    <meta name="robots" content="none" />
+</head>
+<body>
+<h1>Ups...something went wrong with Sabis' Frontend</h1>
+
+
+<table>
+    <tr>
+        <td><img src="/images/Clibanarius.JPG" alt="Clibanarius crap" width="280" height="200"/></td>
+        <td>
+            <p>
+                Sorry for that, but no reason to worry ;-)<br/>
+                <br/>
+                Some exception in the frontend logic occurred I probably haven't considered yet.
+                Please try again: <a href="/">https://sabi-project.net/</a> and if that doesn't fix it
+                consider the suggested feedback in the next paragraph.
+            </p>
+
+            <p>
+                Good news is: YOU can help! First wait a while and try again.
+                If you can reproduce the error please submit a trouble ticket with detail description what happened
+                and led to the problem at: projects <a href="https://github.com/StefanSchubert/sabi/issues">Issues</a>
+                tracker.<br/>
+                Before open an own ticket, have a look if some other already reported a problem and leave a comment
+                there instead.
+            </p>
+
+            <p>
+                Thanks for supporting the project and sorry for any inconvenience caused.
+            </p>
+        </td>
+    </tr>
+</table>
+
+
+</body>
+</html>
\ No newline at end of file