I found the issue now. The problem was that we on one role had set the Update access of a Course to ‘is in author list’. Course doesn’t have an Authors field, which the ‘is in author list’ custom condition implies.
To me it seems pretty extreme to have this small editorial miss crashing the whole admin panel when a user with a role with the above issue logs in. Does anyone have any advice on how to catch and handle this kind of error, in case it would happen again?
Thanks in advance