I'm using the paid version. It was a straight up error (wish I took a screenshot now), I couldn't interact with the game at all. I know I wasn't that far into the game but it's still annoying to lose hours of progress.
I really wish I could figure this one out. As a last case remedy, check if the game you are opening the same one, maybe you have more than one version on Itchio, and you opened a different one after the crash. If not, check if itchio downloaded an update while you played which caused the crash and overwrote the saves. Other than that, I can't really think on what could cause this. I am very sorry.