So I finally solved my editor crash problem but as usual every solution breeds new problems.

Following the documentation in creating a new map this is what happens on the very first step:

http://imageshack.us/photo/my-images/823/accessl.jpg/

What the hell?

Have you tried using a one word name instead of 'new map'? Someone had a problem where their level wouldnt load in pure game mode. We figured out that it was because he named the level 'load'.

CE3 can be very finicky, worth a shot.

Disable UAC.

*shakes fist at UAC*

Create a shortcut and set it to Run As Administrator

(if UAC is the problem)

Stupid UAC. Never occurred to me as a possible fix. I'm familiar with this solution though I cannot remember when it happened before.

Cheers.

I've just tested create map with UAC on default and opening the editor (right click -> Run as Admin) and works just as well as disabling UAC.