addin colision makes me go 2 black screen

[newbymodder]

okay so got it to work for one thing but when i tied to add collision to another object when the game starts it goes to black screen. i transfered a mach to my map then switched it html for my scenery then changed my duplicated itmc for the mach and placed it in my bsp where i wanted it? so why does it make it go black screen. note i also tried just adding the mach to the netgame without swapping an duplicated itmc for it and it still went black screen.

[DarkCloud]

I've had it do this before, I don't know what causes it, but when I openned a clean map and made the same changes again it didn't happen.