diff --git a/rhodecode/lib/dbmigrate/migrate/exceptions.py b/rhodecode/lib/dbmigrate/migrate/exceptions.py
--- a/rhodecode/lib/dbmigrate/migrate/exceptions.py
+++ b/rhodecode/lib/dbmigrate/migrate/exceptions.py
@@ -71,11 +71,6 @@ class InvalidScriptError(ScriptError):
     """Invalid script error."""
 
 
-class InvalidVersionError(Error):
-    """Invalid version error."""
-
-# migrate.changeset
-
 class NotSupportedError(Error):
     """Not supported error"""
 
@@ -83,5 +78,6 @@ class NotSupportedError(Error):
 class InvalidConstraintError(Error):
     """Invalid constraint error"""
 
+
 class MigrateDeprecationWarning(DeprecationWarning):
     """Warning for deprecated features in Migrate"""