Why is my map doing this?

So my map is made for CSS then im moving the BSP to gmod.

So my skybox when I look left (normal) : http://gyazo.com/9faa34283d87f3f91e4286a7c55499aa
When I look right (broken) : http://gyazo.com/42d0b32b05fd89047f37dc30d963d0f9

How do I fix this?

[editline]12th May 2015[/editline]

Bump - changed the question

leak perhaps, either an entity is outside the skybox or the skybox doesn’t close up fully

Leak or a missing texture

Ok I will look into thanks guys, also why do my lights look like this:

Well obvisously if there was a leak you couldent run the map …

What? Of course you can, it’ll just result in some errors, like water not apperaring or those “bleeding edges”.

Those are all missing textures.
Obviously, you are missing either rt/lt/ft/bk textures of your skybox (either .vmf or .vtf or both).

As for the pitch-black ceiling I have no clue. Might be named lights.
I would suggest compiling your maps using Source SDK Base 2013 engine.

P.S: Its not a leak btw.

Its more or less a 50/50, depending on a error you will have a map to run or not.

This is caused by the leak, or if the lights have names

Thanks fixed now!