I share your frustration!!! Like I said, I got the download to work. I think what I did was use Safari to go the main page for Roxio, select Popcorn, and click to download like I was buying it for the first time. Since I had registered the product from the box, Roxio recognized that, so I entered my Key # from the box and then the updated software download began. Even after that, it was a pain to get to work. I figured out that I had to get the download into my applications folder, then drag the downloaded update onto the Popcorn icon in the Applications folder. The first time I tried it, it did not work, but did the second time, and I was finally able to open Popcorn.
Then, the real fun begins. What an obtuse, user-unfriendly program, if you want to do anything other than simply copying a dvd. With a lot of work, I have been able to sort thru some of the maze, and hope that others on this board can get me the rest of the way!