Skybox & EP2 not found

link to movie :

You will see everything on the movie so i dont need to say too much.
My gmod dont finds the EP2 of hl2.
I dont have CS:S .
On gm maps i dont have those glitches , but on RP maps too .
This map name is UD_rebelland_beta_2 or some.

EP2 is messed up. Everyone haves the problem.
No one can fix that (1 man, 1 team, 1 update)
Btw, it’s CS:S what your problem is I guess, cause, almost each map uses CS:S textures.

Btw i asked someone what he see at place where i get error.
They say its standard gmod model ;/ .And pls let some1 fix that bug :stuck_out_tongue:
Oh 1 more question . Can i change the map skybox ? With hammer or some ? And play on it .