I'm experiencing this extremely frustrating issue since installing the itch app a few days ago. Any game I run - most if not all of which are HTML5 games - refuse to run! I have them all installed in an alternate download location (NOT in Program Files nor any other protected folder). I'm unsure as to the cause, but it's about a 50/50 chance on first-time install for the apps through the itch.io app as to whether or not the game will actually launch. I hit launch, and sometimes the game opens immediately, other times nothing happens at all despite the itch app telling me the game is running.
If the latter happens and the game is running despite... not running, force quitting and relaunching the game does nothing. As does reinstalling the game. Going to the game's directory and running it from the file manually works perfectly fine, but running it through the itch app does not. The only way I've found to fix this issue is to completely uninstall the game and then install it again. The issue with this solution is that it goes back to the initial 50/50 chance the game will work on every install, and if something in the game changes (like I enabled a modded version of the game in the settings for example) then once again it goes back to that 50/50 chance that it will work or not.
This is becoming increasingly frustrating, as closing the game and reopening it to fix an issue becomes a coin toss as to whether or not the game will reopen, and I shouldn't have to reinstall games on a regular basis just to get them to work.
I'm on Windows 11, I have not tried to fiddle with Windows Defender's exceptions at all, both the itch app and all relevant games are installed on my HDD in a non-protected folder. There are no errors in the console that I could see that weren't caused by me force quitting games. The games do not crash. There are no leftover processes after quitting the games. The games show as running in the itch app but show no active window and do not launch.