If you're using other languages than English, and updating you must ensure you're having updated language files first - or that you use the administration in English.
If not you'll find youself lost even as Superuser, missing Configuration, Admin Access Controll etc.
Those strings/definitions from database do not load if not in the language files.
Note to devs! A better way to handle missing language strings would be to display the English translation, as many other softwares do. Meaning, having English as a fallback. Example Joomla!
Bookmarks