Im not using any antivirus, here are some error logs I had while playing as USA. The game crashes on every save, even new onesI don't see a clear cause of this in those files.
After one of these crashes can you load up that save and carry on past the crash point?
What antivirus do you use? Make sure victoria3.exe is in all its exceptions lists, AND that it is not doing realtime scans of the Documents/Paradox Interactive/Victoria3 folders