Yep, appears to be an Itch.io Windows app issue. I'll see if I can figure out a rhyme/reason behind it and then get it reported but, in the meantime, might want to recommend downloading from the browser.
Thanks for this great (and fun) product!
I think that maybe I just have to delete the core rules files and re-upload it again or maybe ask the Itch staff if some file didn't get removed correctly. When I make an update I delete the previous version and there is always a confirm check box so maybe is that. If you read this try to download the core rules again and see if happens again since now i'm going to re-upload them and see if that fixes it