Asking this for my friend who is trying to figure out how to get MCC reinstalled, when Halo 3 released on Game Pass PC, it threw this 0x80073D12 error code for him. From what I can tell, this error pertains to when content is trying to be downloaded before a main program is, I recall some people reporting the same issue for the Hot Wheels DLC for Forza Horizon 3 on the Microsoft Store, but he is using the Xbox app. He tried to install the game on a different drive that has no existing copy of the game files, but for whatever reason, it threw the same error code. Anyone else experience this problem?
Nevermind, we managed to fix it.
How did you fix it, having the same problem.