MCC Insider install disappeared. Reinstall broken?

I also submitted a support ticket, but in case anyone else is having the issue has figured it out:

I booted up MCC Insider and got an error that the app was not installed (despite playing yesterday; I assume as a result of the patch?)

Reinstalled game, 15 GB. boots up, but then just sits on a black screen with master chief collection loading icon indefinitely (waited 20+ minutes).

anyone else having this issue? How’d you fix it?

update: rebooting fixed it

Glad to hear you solved it! Hopefully others can benefit from your solution!