I wanted to make a snowy themed version of Hightower for the Nightmare Before Smissmas. I got a decompiled version of it from this website, and everything went fine in Hammer. Once I compiled and opened it in game, it was broken. I'm no expert, so what I say may make no sense, but I think the game is making me see through area portals that are placed in doorways. I also have skybox issues. I capped the cart and that was fine, and all I did in Hammer, so far, was replaced some textures with snow, deleted some props, that weren't important, and kept all the entities, other than props or minor things, exactly how they would be on Hightower. Can someone solve my problem or direct me to somewhere where I can fix it?