Stuck with 9 turn left. population change won't advance.

play a long slow campaign ~60 hours (450 turns). I'm down to my last 9 turns and the game keeps locking on population changes. I have 5 growth and 1 negative and the game keeps cycling through the same 2 acknowledgements. Evan when I disable the notification the game sticks with the loading wheel on the 'next turn' circle. I've gone back an additional 10 turn and sooner or later in the last ~12-9 turns it happens again. I've change city production to limit grown/shrink in every city so there no change in the next 25 turns but still an unattached colony will grow/shrink and it locks again in the acknowledge loop.