I use 2.4.1
In case you have ever been tempted to turn off the server repository, (admin>plugins>repositories) DON'T!!!!
If you have any server files in your course, the action of turning off the server repository will completely (and almost irretrievably) break your course every time. I know, because I did it.
This issue is in tracker 37757, but it is listed as a minor issue. I consider it a major issue, because you can do something easily and that is allowed, and it will always break your course.
The fix is to manually edit your database, but if you don't know how to do that, then you will be out of luck.
Just wanted everyone to know, and I also wanted to give a shout out to David Scotson, who helped me retrieve my course. GREAT JOB David. Thanks.