I created a course backup and renamed it to include a "". When I later tried to restore from it, I got a 404 error, file cannot be found. I then did another backup and did not use a "" sign. This worked, and I could then download it to the file system. I then renamed it to include a "" sign and tried to upload it. It failed again. I then renamed the file to remove the "" sign, after which I was able to use the file to perform a Restore.