The Imperial coop campaign gets stuck on the loading screen after every second battle. The game music continues to play and can be muted with the 'M' key, task manager doesn't consider the game to be unresponsive but the loading screen simply won't go away.
We both have to alt + f4 the game, reload the save before the battle, fight the battle then save again. We then find the next battle then has the same issue.
We've yet to test fighting a battle then save, reload the new save, then fight the next battle.