Does the launcher pull up properly? if not try manually uninstalling or deleting any mods you have in your module folder.
If the launcher does pull up but crashes before you get to the main menu try closing steam and running as an administrator
these are the 2 fixes that have worked for me, some people have been saying that other programs that have overlays (Discord, overwolf, etc.) have caused crashes but I've not had a problem with those. Also heard if you're running at a non-native resolution than it may crash. Again, I've never had this problem but if you try going to steam>bannerlord>right click>properties>Set Launch Options> type in "-windowed" without the quotes. After that you can change the settings in game to what you want