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.