Textures Glitch out in game on my custom map
I have some glitch in my map, I think it happened when I place a spot light covering the whole outside of the map. It makes all the textures invisible(even the grass texture for outside) so all I can see is the skybox. However, I can see the textures in one room if I turn a certain way (BTW: I am using hammer to make this map, AND NO im not a complete noob) I dont know why! I even tried to delete the spotlight, but no avail 
I also even tried changing the skybox back to "sky_black_nofog" instead of "sky_l4d_c4m1_hdr (which is my maps skybox currently)" but every thing is black when I do that! Ive tried every thing and cant find a solution!
Video:
https://www.youtube.com/watch?v=INcwqCXyHMQ&feature=youtu.be&hd=1
EDIT:
Images
That skybox is broken. You shouldnt use it
The skybox is fine, it's just that because it is from l4d2, it has invalid vmt properties. You have to go into the vpk files and extract the skybox vmt files and open them up. Then change the shader from "skybox" to "unlitgeneric" and change ignorerez 1 to ignorerez 0. Then change the names of the vmt files so they don't get overwritten by the defaults.
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thanks ill try that