I'm playing as the Eastern Roman Empire and at the end of my turn 69 the Khwarezmian empire moves one of its armies in Cuman territory, after which I get a CTD. I've reloaded saves multiple times to see if it might be a random occurrence, which I've made sure it isn't.
I'm playing version 6.3 of the game still, since the 6.4 CTDs during startup without fail, regardless of all the fixes I've tried.

Attached below is the log file.If someone could please help me out, that would be very much appreciated.

system.log.rar