Attempting to load L4D models causes Garry's Mod to crash

Hello, Facepunch. I just got L4D, and I wanted to use its content in gmod, but everytime I try to load a model or a custom map that contains L4D content, it takes forever to load. How do I fix this?

System Specs? Addons Installed?

A note: You can’t use L4D Maps in GMod

Nevermind, turns out that the textures and models take a long time load since L4D wasn’t installed yet.

And yes, I already knew that you couldn’t load Default L4D maps. I was talking about the fixed maps by dustils.