So I ran into a problem where all of my games stopped working when attempting to play them. I'd try to test them out, but I'd get a blank screen. I'd upload them to dropbox and same thing.
After some experimentation and a little luck, I've narrowed the problem down to Event Sheet Includes.
Capx!Include Sheet Bug
Try to test it out, and you get a blank screen (if the game's fullscreen mode is set to 'off', it shows the gray border with just gray inside). If you go into Event Sheet 1 and delete the Include Event Sheet 2, another test attempt will show that the game runs fine.
This is probably pretty problematic for complex games.