As you can see, I'm told the application may be damaged, and in the Finder it shows the circle-bar symbol over the app.
My bad, it seems like I totally botched the previous update and some files are missing from the macOS folder, possibly because of a file export problem. My guess is Mac users of the first version weren't affected because Itch's update system didn't remove said files. This is actually good timing because I was about to release a new version with a Dutch translation and a few minor tweaks. Thanks for pointing this out, I'll release a fix in a day or so.