343, please talk to the big guys up stairs or whoever the hell works with this game in the Backwards compatibility section of Xbox One about fixing this stupid issue that shouldn’t exist, I tried launching Halo Reach multiple times already and it fails to start every time before it can load the main menu! I tried re-downloading the game already and that only worked for awhile and failing to launch was the reason I had to delete it. If this is not the place to post this issue about backwards compatible games then point me in the right direction.
It’s Microsoft that manages the backward compatibility feature on the XB1 I believe, it is being worked on, for the time being either play on the good ole 360 or continue the wrenching reinstall process.
Uninstall/reinstall works pretty well. If you need to, unplug your XB1 from the power brick and the wall to reset the RAM/Cloud storage. It does run a lot smoother this way too.