I have never been able to play a game of Halo 2 campaign in co-op. I can play levels by myself. I can play Halo 1, 3, 4, and ODST in co-op. But if I start a game with anybody in the game with me, the game never finishes loading and eventually kicks me and my co-op partner back to the main menu.
I have tried various co-op partners. None of them can start a game with me, although they have been able to start games with each other without problem. I have tried deleting the game and reinstalling it from scratch. I have tried the game on the internal hard drive and on an external drive. I have tried playing as a different account on the same console to see if it was my save file that was somehow the problem. Regardless of what I try, I have never once been able to start up a game of Halo 2 with a co-op partner.
I hope someone else out there has experienced the same issue and can point me at some possible solution? Or even some troubleshooting tips?