Sorry I can't be more specific but I wouldn't even know there was an error if it weren't for the debugger popping on to tell me of a fatal error. Here are what I assume are the two relevant log files to study.
The only real weird accidental behavior on my part this game that could be relevant, I had resource piles placed in opposing faction's cities (red faction's rock pile there in blue faction's city limits). A fun newbie mistake as I forgot who's turn it was that moment.