This updated for Windows 11 tutorial guide shows how you can fix your missing textures and error models issue in Garry's Mod by importing Counter Strike Source Content.
CSS Game Content: https://drive.google.com/drive/folder...
Previous Windows 10 guide: • How to FIX Missing Textures for Garry's Mod
Map used in the video: https://steamcommunity.com/sharedfile... (Freddy Fazbear's Pizza)
I hope this helped you out!