Whenever I try to load up any mission for Halo 3: ODST, I get stuck in the loading screen and it just sits there endlessly. All of the other campaigns load up fine. I’ve tried uninstalling and reinstalling the game and still nothing. I hope I’m not the only one experiencing this issue. 
I would try launching the game from the playlist menu and see if that solves your issues
> 2533274841455840;2:
> I would try launching the game from the playlist menu and see if that solves your issues
Thank you for the suggestion. Unfortunately that didn’t work either.