I own Halo MCC on PC with Gamepass Ultimate. I have the game installed and when I go to launch the game, either through the xbox app, the microsoft store or from the start menu the game will load and show the logos for 343I and Microsoft Studios but it will then close and load up the microsoft store page telling me I need to install Reach.
Same problem here, it seems that no one is talking about it.
I’ve been searching for a solution to tthis problem since yesterday, but i haven’t found anything.
I’m also having the same issue. Reinstalling the game didn’t fix the issue either.
Please see the pinned thread regarding Halo Support and how to submit tickets for issues you may be experiencing.