If you get a fatal error when starting Halo:MCC on gamepass I found a fix. Steam users have had a lot of success forcing -windowed mode by editing the options/shortcut. This isn’t an option for the Gamepass version.
So I thought I would finally install Geforce Experience. I don’t like some of their privacy policies, having to log in, etc. so I never used it. But I was desperate for a fix so I could play.
You can use it to force windowed mode, change the graphic settings before you even attempt to load the game. I’ve had a lot of luck forcing windowed mode in a resolution lower than my monitor even before the game tries to load. In my case it was windowed, 1080p, graphics set to optimized.
Hope this works for other people with Nvidia cards and the Gamepass version!