Error/cannot finish ui if not setting u

You may experience the error cannot finish ui if not setting u when attempting to back up a course. It is most likely due to a 'broken' custom plugin on your site.

To resolve the problem, make sure all your plugins are up to data and delete any that you don't use. If the problem remains, you may have to delete/disable all the plugins and add them back one at a time to identify the culprit.