diff --git a/.gitignore b/.gitignore
index a5b2d53..87597a1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,4 +11,4 @@
 *.test
 
 # Output of the go coverage tool, specifically when used with LiteIDE
-*.out
+*.out
\ No newline at end of file
diff --git a/README.md b/README.md
index 4b4aa7a..6c57b19 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,7 @@ GoSDDL (Security Descriptor Definition Language)
 [![Build Status](https://travis-ci.org/MonaxGT/gosddl.svg?branch=master)](https://travis-ci.org/MonaxGT/gosddl)
 [![Codacy Badge](https://api.codacy.com/project/badge/Grade/70d6bf54dd2547d894ee7ba7a9247285)](https://app.codacy.com/app/MonaxGT/gosddl?utm_source=github.com&utm_medium=referral&utm_content=MonaxGT/gosddl&utm_campaign=Badge_Grade_Dashboard)
 [![Maintainability](https://api.codeclimate.com/v1/badges/69e05e119408b9f830d4/maintainability)](https://codeclimate.com/github/MonaxGT/gosddl/maintainability)
+[![Go Report Card](https://goreportcard.com/badge/github.com/MonaxGT/gosddl)](https://goreportcard.com/report/github.com/MonaxGT/gosddl)
 
 Converter from SDDL-string to user-friendly JSON. SDDL consist of four part: Owner, Primary Group, DACL, SACL.
 This converter works with two mode:
@@ -57,4 +58,4 @@ docker run --rm -it -v $PWD/store:/app/data gosddl "O:BAG:SYD:(D;;GA;;;AN)(D;;GA
 
 Links:
 
-[Source](https://docs.microsoft.com/en-us/windows/desktop/secauthz/security-descriptor-definition-language)
+[Source](https://docs.microsoft.com/en-us/windows/desktop/secauthz/security-descriptor-definition-language)
\ No newline at end of file
diff --git a/gosddl.go b/gosddl.go
index d19d596..e40d83c 100644
--- a/gosddl.go
+++ b/gosddl.go
@@ -9,11 +9,12 @@ import (
 	"strings"
 
 	"encoding/json"
+	"github.com/pkg/errors"
 )
 
 // ACLProcessor main struct with methods
 type ACLProcessor struct {
-	Rights Permissons
+	Rights permissons
 	File   string
 }
 
@@ -26,7 +27,7 @@ type entryACL struct {
 	InheritObjectGUID string   `json:"inheritObjectGUID,omitempty"`
 }
 
-type Permissons struct {
+type permissons struct {
 	Owner     string     `json:"owner,omitempty"`
 	Primary   string     `json:"primary,omitempty"`
 	Dacl      []entryACL `json:"dacl,omitempty"`
@@ -165,7 +166,7 @@ func (app *ACLProcessor) sliceSDDL(indecs []int, str string) {
 }
 
 // FindGroupIndex used for find index of group Owner, Primary, DACL, SACL
-func (app *ACLProcessor) findGroupIndex(str string) {
+func (app *ACLProcessor) findGroupIndex(str string) error {
 	groups := []string{"O:", "G:", "D:", "S:"}
 	var result []int
 	for _, i := range groups {
@@ -173,25 +174,34 @@ func (app *ACLProcessor) findGroupIndex(str string) {
 			result = append(result, strings.Index(str, i))
 		}
 	}
+	if result == nil {
+		return errors.New("Can't find any group")
+	}
 	result = append(result, len(str))
 	app.sliceSDDL(result, str)
+	return nil
 }
 
 // Processor main function in gosddl package
-func Processor(api bool, port string, file string) {
+func Processor(api bool, port string, file string) error {
 	var app ACLProcessor
 	app.File = file
 	if api {
 		fmt.Println("API Interface started on port", port)
 		app.httpHandler(port)
 	} else if flag.Args() != nil {
-		app.findGroupIndex(flag.Args()[0])
+		err := app.findGroupIndex(flag.Args()[0])
+		if err != nil {
+			return err
+		}
 		body, err := json.Marshal(app.Rights)
 		if err != nil {
 			log.Fatal(err)
+			return err
 		}
 		fmt.Println(string(body))
-	} else {
-		log.Fatal("You should give me SDDL string or use API mode")
+		return nil
 	}
-}
+	log.Fatal("You should give me SDDL string or use API mode")
+	return nil
+}
\ No newline at end of file
diff --git a/http.go b/http.go
index d16d800..ce735bc 100644
--- a/http.go
+++ b/http.go
@@ -16,8 +16,12 @@ func (app *ACLProcessor) decode(w http.ResponseWriter, r *http.Request) {
 	params := mux.Vars(r)
 	if params["sddl"] != "" {
 		sddl := params["sddl"]
-		app.findGroupIndex(sddl)
+		err := app.findGroupIndex(sddl)
+		if err != nil {
+			log.Println("Wrong SDDL string")
+		}
 		json.NewEncoder(w).Encode(app.Rights)
+		app.Rights = permissons{}
 		return
 	}
 }
@@ -27,4 +31,4 @@ func (app *ACLProcessor) httpHandler(port string) {
 	router.HandleFunc("/sddl", getInfo).Methods("GET")
 	router.HandleFunc("/sddl/{sddl}", app.decode).Methods("GET")
 	log.Fatal(http.ListenAndServe(port, router))
-}
+}
\ No newline at end of file
diff --git a/http_test.go b/http_test.go
index 584449f..7d9e172 100644
--- a/http_test.go
+++ b/http_test.go
@@ -23,4 +23,4 @@ func TestGetInfo(t *testing.T) {
 		t.Errorf("handler returned unexpected body: got %v want %v",
 			rr.Body.String(), expected)
 	}
-}
+}
\ No newline at end of file
diff --git a/maps.go b/maps.go
index 8977600..a34ca57 100644
--- a/maps.go
+++ b/maps.go
@@ -181,4 +181,4 @@ var sddlWellKnownSidsRep = map[string]string{
 	"S-1-5-32-579": "BUILTIN\\Access Control Assistance Operators",
 	"S-1-5-32-580": "BUILTIN\\Remote Management Users",
 	"S-1-5-80-956008885-3418522649-1831038044-1853292631-2271478464": "Trusted Installer",
-}
+}
\ No newline at end of file
diff --git a/service/gosddl/main.go b/service/gosddl/main.go
index d661fe7..2a94773 100644
--- a/service/gosddl/main.go
+++ b/service/gosddl/main.go
@@ -11,5 +11,8 @@ func main() {
 	apiPortPtr := flag.String("port", ":8000", "Default port 8000")
 	fileSIDs := flag.String("f", "", "File with users's SIDs")
 	flag.Parse()
-	gosddl.Processor(*apiPtr, *apiPortPtr, *fileSIDs)
-}
+	err := gosddl.Processor(*apiPtr, *apiPortPtr, *fileSIDs)
+	if err != nil {
+		panic(err)
+	}
+}
\ No newline at end of file