diff --git a/src/main/java/org/tkit/onecx/permission/bff/rs/controllers/AssignmentRestController.java b/src/main/java/org/tkit/onecx/permission/bff/rs/controllers/AssignmentRestController.java
index 52ec553..a9bfd33 100644
--- a/src/main/java/org/tkit/onecx/permission/bff/rs/controllers/AssignmentRestController.java
+++ b/src/main/java/org/tkit/onecx/permission/bff/rs/controllers/AssignmentRestController.java
@@ -6,10 +6,10 @@
 import jakarta.inject.Inject;
 import jakarta.transaction.Transactional;
 import jakarta.validation.ConstraintViolationException;
-import jakarta.ws.rs.WebApplicationException;
 import jakarta.ws.rs.core.Response;
 
 import org.eclipse.microprofile.rest.client.inject.RestClient;
+import org.jboss.resteasy.reactive.ClientWebApplicationException;
 import org.jboss.resteasy.reactive.RestResponse;
 import org.jboss.resteasy.reactive.server.ServerExceptionMapper;
 import org.tkit.onecx.permission.bff.rs.mappers.AssignmentMapper;
@@ -179,7 +179,7 @@ public RestResponse<ProblemDetailResponseDTO> constraint(ConstraintViolationExce
     }
 
     @ServerExceptionMapper
-    public Response restException(WebApplicationException ex) {
-        return Response.status(ex.getResponse().getStatus()).build();
+    public Response clientRestException(ClientWebApplicationException ex) {
+        return exceptionMapper.clientException(ex);
     }
 }
diff --git a/src/main/java/org/tkit/onecx/permission/bff/rs/mappers/ExceptionMapper.java b/src/main/java/org/tkit/onecx/permission/bff/rs/mappers/ExceptionMapper.java
index 9d27639..86bbd23 100644
--- a/src/main/java/org/tkit/onecx/permission/bff/rs/mappers/ExceptionMapper.java
+++ b/src/main/java/org/tkit/onecx/permission/bff/rs/mappers/ExceptionMapper.java
@@ -20,6 +20,7 @@
 import gen.org.tkit.onecx.permission.bff.rs.internal.model.ProblemDetailInvalidParamDTO;
 import gen.org.tkit.onecx.permission.bff.rs.internal.model.ProblemDetailParamDTO;
 import gen.org.tkit.onecx.permission.bff.rs.internal.model.ProblemDetailResponseDTO;
+import gen.org.tkit.onecx.permission.exim.client.model.EximProblemDetailResponse;
 import gen.org.tkit.onecx.permission.model.ProblemDetailResponse;
 
 @Mapper(uses = { OffsetDateTimeMapper.class })
@@ -65,6 +66,9 @@ default String mapPath(Path path) {
     default Response clientException(ClientWebApplicationException ex) {
         if (ex.getResponse().getStatus() == 500) {
             return Response.status(400).build();
+        } else if (ex.getResponse().getStatus() == 409) {
+            return Response.status(ex.getResponse().getStatus())
+                    .entity(mapImportException(ex.getResponse().readEntity(EximProblemDetailResponse.class))).build();
         } else {
             if (ex.getResponse().getMediaType() != null
                     && ex.getResponse().getMediaType().toString().contains(APPLICATION_JSON)) {
@@ -76,6 +80,10 @@ default Response clientException(ClientWebApplicationException ex) {
         }
     }
 
+    @Mapping(target = "removeParamsItem", ignore = true)
+    @Mapping(target = "removeInvalidParamsItem", ignore = true)
+    ProblemDetailResponseDTO mapImportException(EximProblemDetailResponse eximProblemDetailResponse);
+
     @Mapping(target = "removeParamsItem", ignore = true)
     @Mapping(target = "removeInvalidParamsItem", ignore = true)
     ProblemDetailResponseDTO map(ProblemDetailResponse problemDetailResponse);
diff --git a/src/test/java/org/tkit/onecx/permission/rs/AssignmentRestControllerTest.java b/src/test/java/org/tkit/onecx/permission/rs/AssignmentRestControllerTest.java
index 1909141..8582116 100644
--- a/src/test/java/org/tkit/onecx/permission/rs/AssignmentRestControllerTest.java
+++ b/src/test/java/org/tkit/onecx/permission/rs/AssignmentRestControllerTest.java
@@ -24,6 +24,8 @@
 import gen.org.tkit.onecx.permission.bff.rs.internal.model.*;
 import gen.org.tkit.onecx.permission.client.model.*;
 import gen.org.tkit.onecx.permission.exim.client.model.AssignmentSnapshot;
+import gen.org.tkit.onecx.permission.exim.client.model.EximProblemDetailInvalidParam;
+import gen.org.tkit.onecx.permission.exim.client.model.EximProblemDetailResponse;
 import gen.org.tkit.onecx.permission.exim.client.model.ExportAssignmentsRequest;
 import io.quarkiverse.mockserver.test.InjectMockServerClient;
 import io.quarkus.test.common.http.TestHTTPEndpoint;
@@ -462,6 +464,51 @@ void importAssignmentsTest() {
 
     }
 
+    @Test
+    void importAssignments_exception_mapping_Test() {
+        AssignmentSnapshot assignmentSnapshot = new AssignmentSnapshot();
+        assignmentSnapshot.setAssignments(Map.of("product1",
+                Map.of("app1", Map.of("role1", Map.of("resource1", List.of("read", "write"))))));
+
+        EximProblemDetailResponse eximProblemDetailResponse = new EximProblemDetailResponse();
+        eximProblemDetailResponse.setDetail("some Detail");
+        EximProblemDetailInvalidParam invalidParam = new EximProblemDetailInvalidParam();
+        invalidParam.setName("param1");
+        invalidParam.setMessage("duplicated key");
+        eximProblemDetailResponse.setInvalidParams(List.of(invalidParam));
+        // create mock rest endpoint
+        mockServerClient.when(request().withPath("/exim/v1/assignments/import").withMethod(HttpMethod.POST)
+                .withBody(JsonBody.json(assignmentSnapshot)))
+                .withId("MOCK_ID")
+                .respond(httpRequest -> response()
+                        .withStatusCode(Response.Status.CONFLICT.getStatusCode())
+                        .withBody(JsonBody.json(eximProblemDetailResponse)));
+
+        AssignmentSnapshot assignmentSnapshotDTO = new AssignmentSnapshot();
+        assignmentSnapshotDTO.setAssignments(Map.of("product1",
+                Map.of("app1", Map.of("role1", Map.of("resource1", List.of("read", "write"))))));
+
+        var output = given()
+                .when()
+                .auth().oauth2(keycloakClient.getAccessToken(ADMIN))
+                .header(APM_HEADER_PARAM, ADMIN)
+                .contentType(APPLICATION_JSON)
+                .body(assignmentSnapshotDTO)
+                .post("/import")
+                .then()
+                .contentType(APPLICATION_JSON)
+                .statusCode(Response.Status.CONFLICT.getStatusCode())
+                .extract().as(ProblemDetailResponseDTO.class);
+
+        Assertions.assertNotNull(output);
+        Assertions.assertEquals(output.getDetail(), eximProblemDetailResponse.getDetail());
+        Assertions.assertEquals(output.getInvalidParams().get(0).getName(),
+                eximProblemDetailResponse.getInvalidParams().get(0).getName());
+
+        mockServerClient.clear("MOCK_ID");
+
+    }
+
     @Test
     void searchUsersAssignmentsByCriteriaTest() {