diff --git a/ucs-4.0-0/management/univention-management-console-frontend/umc/tools.js b/ucs-4.0-0/management/univention-management-console-frontend/umc/tools.js
index 0e09475..08c5ce7 100644
--- a/ucs-4.0-0/management/univention-management-console-frontend/umc/tools.js
+++ b/ucs-4.0-0/management/univention-management-console-frontend/umc/tools.js
@@ -666,6 +666,9 @@ define([
 					// validation error
 					topic.publish('/umc/actions', 'error', status);
 					handleErrors.onValidationError(message, result);
+				} else if (503 == status && dialog._loginDialog && dialog._loginDialog.get('open')) {
+					// either the UMC-server or the UMC-Web-Server is not runnning
+					dialog._loginDialog.updateForm(false, statusMessage);
 				}
 				/*else if (591 == status) {
 					// the command could not be executed, e.g., since the user data was not correct
diff --git a/ucs-4.0-0/management/univention-management-console-frontend/univention-management-console-web-server b/ucs-4.0-0/management/univention-management-console-frontend/univention-management-console-web-server
index e2115fb..73cb5f8 100755
--- a/ucs-4.0-0/management/univention-management-console-frontend/univention-management-console-web-server
+++ b/ucs-4.0-0/management/univention-management-console-frontend/univention-management-console-web-server
@@ -280,10 +280,11 @@ class UMCP_Dispatcher(object):
 				# add a small offset to the timeout in order to avoid a mismatch between frontend and backend
 				try:
 					client = SessionClient(timeout=_session_timeout + 5, ip=queuerequest.ip, cookie=queuerequest.cookie)
-				except Exception as e:
-					CORE.process('Failed to create UMC connection: %s' % str(e))
+				except Exception as exc:
+					CORE.process('Failed to create UMC connection: %s' % (exc, ))
 					response = umcp.Response(queuerequest.request)
-					response.status = httplib.UNAUTHORIZED  # set status to unauthorized
+					response.status = httplib.SERVICE_UNAVAILABLE
+					response.message = 'The UMC-server is currently not running. Please try again later.'
 					queuerequest.response_queue.put(response)
 					continue