Ok, So Seraphinexx and I tested for nearly 3 hours to find out exactly what causes issues with Windows 8 and online games And I think we've tested all possible scenarios.
If at any time in a gaming session 1 coop mission is played, be it won or lost, the very next game, be it Coop, Multiplayer Battle or any other game mode, or even Single Player (mission or skirmish) the game will crash and shut down. And it doesn't matter whether the coop is played at the beginning of the session, or somewhere in the middle.
Even if after a coop, player 1 hosts a new game and some one else jumps in, Player 1 who had the coop, will crash and the other, new, player will remain locked in the loading screen.
However, Player 2 from that coop, will have the same issues if he tries to play a game (hosted himself or not) with some one else after the coop and the other new player will also remain stuck in the loading screen
The only way around this issue that is known to us, is that after 1 coop has been played, the game has to be completely shut down (launcher is excluded from this proces) and restarted.
The crash message, was: The main executable for Mental Omega has stopped working, btw
Edited by Hecthor Doomhammer, 06 December 2013 - 11:13 AM.