[RUNGSI]

oh man.. your screwed
Never use CSG Subtract.
Never ever ever.
What i am trying to say is.
NEVER USE CSG SUBTRACT!!!
when you use it, its not only cutting the brush you want.. but cuts ALL BRUSHES in the map.
Sounds like you probablly exceed the amount of brushes used. and too much for the program to see to open.

Only hope for you is ethier
1. send the .map file to another user. see if he gets same error.
2. If you use winXP, use system restore, and go back 1 day
3. Start all over. But this time. DONT USE CSG SUBTRACT

I would recommend starting over. The damage is done.