AUGUSTUSAM
Chieftain
This error is unrelated to the MOD, it sometimes happens in normal CIV too. It must be related to either some "wrong move" that the AI makes or to some memory problem. I managed to go by this error by loading the last autosave and then doing everything totally differently. The computer will calculate different moves and maybe the error won't occur again.
I will try that as I kept doing basically the same moves after I restarted. It was almost 12 Am and I had work the next morning at 7:30 so I did not experiment further.