Many years ago I bought QuickTime Pro. It has been moderately useful and updated to the current version. Twice now all my bought downloads have disappeared from my computer and from my Apple page, including QuickTime Pro in each case. Over the last two month with the help of AppleCare I have restored everything else (I think) from the last disaster. But although I enter my code into the QuickTime Registration panel, nothing happens except that my code disappears. There is nothing wrong with my code which is written down on my MacBook and on paper. The problem is somewhere else and presumably with either Apple or the QuickTime service.