map Crash Startup

hi. been working on my map forawhile any who. i just compiled it and now when i go to load it i select the map and it then loads for about 1/2 a sec and returns to the main menu.....

ive tryed to compile in the counter strike settings, tf2, hl2, ep 1,2 and deathmatch. still no sucess.

wait i found the problem. what happend was there was 2 brushes which didnt have a bottom. (dont ask me how) but there was the top, 4sides but no bottom. i deleted the solid and then redrew it. worked like a charm .

THANKS FOR THE RESPONSE (time for the entertaining optomosation)