Hi Stardockians just reporting a bug where if a city is attacked twice by the AI the 2nd attack doesnt happen but you can no longer carry out any more attacks and can no longer end the turn - it basically forces you to exit the game completely and load up the save.
It actually breaks the game when you're being attacked by a horde of troops because you're pretty much guaranteed to get attacked twice and each time this happens you have to restart 
