Purchased a few courses, and i always download them to hardrive to keep for future reference. The first course i bought a while back was the ableton for beginners which ive had no problem viewing numerous times until now. Its a html file so obv its being sent from your server. I receive the page with sound when it plays but no picture shows.
I also purchased the french electro ableton course and that still works perfectly on Quicktime at the minute. I have reinstalled the latest version and it still the same problem still arises.