I have the same issue. The game randomly crashes (sometimes even complete bluescreen) after 30-60 min. playing. If its not a bluescreen, still only a complete computer restart helps.
Ingame its random, sometimes while attacking some looters, sometimes while walking in a town, most of the time if I try to save or try to load (ingame).
Only thing I found is that bannerlord is useing more and more RAM (I saw it useing up to 23GB of my 32 GB). My guess for the bluescreens and crashes is that my system just runs out of free memory at some point.
I'm playing with the "Very low" settings, because my specs sadly are not much above the minimum requirements:
- OS: Windows10 (tried with Win7 on patch .0, .1, .2, then upgraded os to Win10 -> issue still here with .3, .4 and the current .5)
- CPU: i7-3770K (3.50 GHz)
- GPU: GTX680 (-> might be my main issue?)
- RAM: 32GB
Edit: Each time i checked the performance settings if it uses the right gpu and if the settings are still all on very low, tested with a complete new campaign on the respective game version, checked if the (gpu, nvidia) drivers are updated and closed everything else running on my system (even windows defender and the antivirus software).