i had this problem long time ago ....
sometimes the game crashed while mapchange...
This fixed it:
1. remove all c++ redistributables
2. delete the rgl_config file (%\Documents\Mount&Blade Warband)
3. Start Warband
4. If you still have the problem, repeat step 1 , delete the complete Save folder (%\Documents\Mount&Blade Warband <== this) and the Warband folder you can reach with run ( windows + R), %appdata% ...
5. If step 4 didn't helped, reinstall windows