Description: This error is almost always caused by an invalid brush, by having huge rooms, or scaling a texture down to extremely small values (between -1 and 1)
How to Fix: Find the invalid brush. Any imported prefabs, carved brushes, or vertex manipulated brushes should be suspect
I'm not sure how to fix....
Check it out....It's not much of a map, i know....i just learned how to make them 3 hours ago but here u go.....
Your giant room is too big, and is missing walls on two sides.
Make it about 10% smaller. Having stuff close to the edge of the grid causes problems. Although your problem is probably the giant gaping leaks on both sides of your map.
Oh man....i see now, Thanks! I didn't see those two sides because i was looking at the side view and all 4 corners were sealed, but i see now, thanks bud!