I'm not sure. I was never able to get your last save to crash on my system during several attempts to enter the city, but did find some errors in the logs that I resolved in the update yesterday, but since they didn't cause me to crash, they may not be contributing to your problem and it might be something else.
You can try providing another save before entering a city. But in addition, attack the city, and if it crashes, also send me the system.log, compile.log and an error.log file (if you see one). Those 4 things and I'll see if I can recreate your problem.