Is it because I kept the old backup?
i'm not sure what the problem might be, if you're talking about the itch.io app then it might be some problem with it because i have never checked if that worked with the game, but it might be a problem with the installation?
if you're on windows there is a known problem when rendering for some people that can be solved by
- launch the game -> shift + g -> change rendeerer -> close and open again