If a try to backup a course, nothing happens after I clik on 'perform backup'. I've read a lot in this forum about similar problems, but I could't find anything that helps. I can backup all other courses, just this one doesn't work. I tried to select less activities, but I get the same, after clicking on 'perform backup' I just get a blank page. I have even tried to backup just one activity: nothing. What can be wrong with this course??
Do anyone have an idea, what could I try?