diff --git a/management/univention-management-console/src/univention/management/console/base.py b/management/univention-management-console/src/univention/management/console/base.py
index faf71e2138..72065834a2 100644
--- a/management/univention-management-console/src/univention/management/console/base.py
+++ b/management/univention-management-console/src/univention/management/console/base.py
@@ -126,7 +126,7 @@ def query(self, request):
 from univention.management.console.ldap import get_user_connection, reset_cache as reset_ldap_connection_cache
 from univention.management.console.config import ucr
 from univention.management.console.log import MODULE, CORE
-from univention.management.console.error import UMC_Error, NotAcceptable, PasswordRequired, LDAP_ServerDown, LDAP_ConnectionFailed, Unauthorized
+from univention.management.console.error import UMC_Error, NotAcceptable, PasswordRequired, LDAP_ServerDown, LDAP_ConnectionFailed
 
 _ = Translation('univention.management.console').translate
 
@@ -299,17 +299,14 @@ def error_handling(self, etype, exc, etraceback):
 		:param exc: The exception instance.
 		:param etraceback: The exception traceback instance; may be None.
 		"""
-		if isinstance(exc, udm_errors.ldapError) and isinstance(getattr(exc, 'original_exception', None), ldap.SERVER_DOWN):
-			exc = exc.original_exception
-		if isinstance(exc, udm_errors.ldapError) and isinstance(getattr(exc, 'original_exception', None), ldap.INVALID_CREDENTIALS):
+		if isinstance(exc, udm_errors.ldapError) and isinstance(getattr(exc, 'original_exception', None), (ldap.SERVER_DOWN, ldap.INVALID_CREDENTIALS)):
 			exc = exc.original_exception
 		if isinstance(exc, ldap.SERVER_DOWN):
 			raise LDAP_ServerDown()
-		if isinstance(exc, ldap.CONNECT_ERROR):
+		if isinstance(exc, (ldap.CONNECT_ERROR, ldap.INVALID_CREDENTIALS)):
 			raise LDAP_ConnectionFailed(exc)
 		if isinstance(exc, ldap.INVALID_CREDENTIALS):
 			reset_ldap_connection_cache()
-			raise Unauthorized
 
 	def __error_handling(self, request, method, etype, exc, etraceback):
 		"""
diff --git a/management/univention-management-console/src/univention/management/console/error.py b/management/univention-management-console/src/univention/management/console/error.py
index 74754fcaad..a846489022 100644
--- a/management/univention-management-console/src/univention/management/console/error.py
+++ b/management/univention-management-console/src/univention/management/console/error.py
@@ -143,7 +143,7 @@ def __init__(self, exc):
 
 	def _error_msg(self):
 		yield _('Cannot connect to the LDAP service.')
-		yield _('Error message: %s') % (self.exc.args[0].get('info', ''),)
+		yield _('Error message: %s') % (self.exc.args[0].get('info', self.exc.args[0].get('desc', '')),)
 		yield ''
 		yield _('The following steps can help to solve this problem:')
 		if not self._is_master:
diff --git a/management/univention-management-console/src/univention/management/console/protocol/session.py b/management/univention-management-console/src/univention/management/console/protocol/session.py
index 71bdc97d6e..724c6855eb 100644
--- a/management/univention-management-console/src/univention/management/console/protocol/session.py
+++ b/management/univention-management-console/src/univention/management/console/protocol/session.py
@@ -149,7 +149,10 @@ class ProcessorBase(Base):
 
 	@property
 	def lo(self):
-		return get_machine_connection(write=False)[0]
+		try:
+			return get_machine_connection(write=False)[0]
+		except ldap.INVALID_CREDENTIALS as exc:
+			CORE.info('Could not get machine connection: %s' % (exc,))
 
 	def __init__(self):
 		Base.__init__(self, 'univention-management-console')