Hi! What you're describing sounds like a file permission issue, possibly related to where and/or how you've installed the game. If you haven't yet, please try installing the game using the Itch app, which should solve any file permission issues: https://itch.io/app
If the game still doesn't run after that, you may have a version of MacOS that is less compatible with RPG Maker MV made games than older versions of MacOS, in which case feel free to apply for a refund through Itch's refund system (we creators can't handle refunds manually)