Here is how the bug seems to break the game in Multiplayer
AI players with human players
player 1 hit end turn
player 2 hit end turn
AI players do there turns
Player 1 hit end turn
then says waiting for player
player 2 is able to do stuff - even though the waiting for players thing still on the screen
player 2 hits end turn - it still ways waiting for player
and game is then stuck waiting for player even though the player has hit the end turn button.
games then broken you do a save try restore sometimes it work again save sometimes not.