diff --git a/frontend/app/lib/model/services/backend_service.dart b/frontend/app/lib/model/services/backend_service.dart
index d3e8e86..3b58a3f 100644
--- a/frontend/app/lib/model/services/backend_service.dart
+++ b/frontend/app/lib/model/services/backend_service.dart
@@ -225,6 +225,9 @@ class BackendService {
     } on SocketException {
       throw FetchDataException('Keine Internet Verbindung');
     } on GrpcError catch (err) {
+      if (err.code == 12) {
+        throw UnauthorizedException('${err.message}');
+      }
       throw FetchDataException('${err.message}');
     } catch (err) {
       throw InternalException(err.toString());