diff --git a/src/caosdb/common/models.py b/src/caosdb/common/models.py
index 5bc1983c56b4c1bdb7b8c7a0fcc194c9d64c9296..86e055cc20c30be05a610b4fb99800834c3c451f 100644
--- a/src/caosdb/common/models.py
+++ b/src/caosdb/common/models.py
@@ -54,15 +54,16 @@ from ..configuration import get_config
 from ..connection.connection import get_connection
 from ..connection.encode import MultipartParam, multipart_encode
 from ..exceptions import (AmbiguousEntityError, AuthorizationError,
-                          CaosDBConnectionError, CaosDBException,
                           ConsistencyError, EmptyUniqueQueryError,
                           EntityDoesNotExistError, EntityError,
                           EntityHasNoDatatypeError, HTTPURITooLongError,
-                          MismatchingEntitiesError, QueryNotUniqueError,
-                          TransactionError, UniqueNamesError,
-                          UnqualifiedParentsError, PagingConsistencyError,
+                          LinkAheadConnectionError, LinkAheadException,
+                          MismatchingEntitiesError, PagingConsistencyError,
+                          QueryNotUniqueError, TransactionError,
+                          UniqueNamesError, UnqualifiedParentsError,
                           UnqualifiedPropertiesError)
-from .datatype import BOOLEAN, DATETIME, DOUBLE, INTEGER, TEXT, is_reference, is_list_datatype
+from .datatype import (BOOLEAN, DATETIME, DOUBLE, INTEGER, TEXT,
+                       is_list_datatype, is_reference)
 from .state import State
 from .timezone import TimeZone
 from .utils import uuid, xml2str