itch.io

Hi mate! First off, sorry you're having issues! I hate when this happens :( I'm not very "in the know" with the Mac OS but that error doesn't sound familiar to me at all actually! I know there are some issues with permissions or the like when deploying a Mac version from a Windows PC. A user linked me a video way back about 18 months ago that has helped Mac users with that particular problem:

I dunno if this is even applicable to the problem you're having but it's a working fix for the only known Mac issue. I hope this isn't coming across condescending or anything mate, I've just relied heavily on users when it comes to the Mac version as I have no access to one to try things myself. I can contact support on here (I just googled and apparently that's the only way to issue a refund on itch.io, I'm very new to these parts ^_^) to get a refund sent mate! I'll be online for the rest of the evening if you're around and maybe we can find a fix together if the above one doesn't work :)