Fehler beim Update: fk.order.created_by_id

Beim Versuch, auf 6.4.3.0 zu Updated, erhalte ich einen Fehler:

Error Received the following error message: An exception occurred while executing 'ALTER TABLE `order` DROP FOREIGN KEY `fk.order.created_by_id`': SQLSTATE[42000]: Syntax error or access violation: 1091 Can't DROP FOREIGN KEY `fk.order.created_by_id`; check that it exists  Please try to fix this error and restart the update. Response  {"valid":false,"errorMsg":"An exception occurred while executing 'ALTER TABLE `order` DROP FOREIGN KEY `fk.order.created_by_id`':\n\nSQLSTATE[42000]: Syntax error or access violation: 1091 Can't DROP FOREIGN KEY `fk.order.created_by_id`; check that it exists"}

HILFE!