The areas in the regular game open fine, but when I try to go to the Crägholdt Bluffs, or to any area in the White March, the game aborts and sends me to the main menu. If I try to open a game save from the White March area, same thing, but I also get an error message saying there was an error opening the map.

I tried reinstalling the game, but I get the same problem.

EDIT:

Never mind, problem solved. Turned out there was also a new version of White March I needed to download, to replace the old one.