I'm getting a crash to desktop with the error message "medieval 2 has encountered an unspecified error and will now exit" when a select to fight a battle myself rather than autoresolve.
I have 4.2, HHB & HHB bugfix installed and I'm playing as HRE. The game originally had a CTD on grand campaign start which I was able to fix based on some earlier advice in this thread (I copied the "northern_general_01.tga.dds" file from the main folder to the mod folder).