My friend and I have been playing Gears co-op all week. Tonight, he cannot connect to me to continue playing our game. He's getting a "connection to host session failed. you cannot join the game session" error. I can connect to other multiplayer games, so can he. I can also join his games, he just can't join mine.
Anybody have any idea why this would happen out of the blue? I have changed no settings at all with my XBOX, router, or modem.