by Ken Task.
'gives me an error' ... could you provide some more info about that?
Can see the progress indicator appears to stop on uploading but other than that no specific information to go on to attempt to suggest a resolution to the problem.
So two things ... turn on debugging (all the way to developer) and attempt to restore same course. Return to this threa and post the debug output. OR/AND check apache error logs ... assuming apache as you've not given any specs about the server. Sometimes those logs provide hints/clues as to the issue.
'spirit of sharing', Ken