Have you used mods at all ? Maybe on different playthrough. I have also had something like this but with mods . All the original faction leaders were dead new leaders ruled some clans were on their 3rd leader. Every time the Aseri leader got killed the game crashed. As for mods remnants remain in the game folder an in my documents bannerlord folder these can make the game crash or if the games updated. what you could try is go to my documents bannerlord copy and save the save game folder to desk top. Uninstall bannerlord and the n delete both the steam bannerlord folder and the my documents folder. then reinstall and put your saves back. If you never used mod ever then maybe my crashes were the game and not the mods?.