I'm having the same unhandled exception error now too. I haven't installed anything at all since yesterday (when it was working fine). I've installed the new .NET beta framework today after getting this error and still have the same error message.
This is by far the best mod and I want to keep using it - it still works fine on my wife's pc so at least I can copy the updated files from her pc for now.
Any ideas on a solution for this problem?
[edit] I just installed the 0.97 beta of the map updater and it works fine now
