Same issue here! Has anyone come across a solution? I also have a free demo so I can't find an option for an alternative download.
Viewing post in .ZIP Files getting corrupted on download
Ah well, I'm sure they're working on it. I was looking around more though, even though my download is free,I was able to get the "Downloads not starting?" button to work. I'm not sure if it's because I have a second optional file you can download, (it's a .txt file with credits for the assets I used), but it seemed to work for me for now!