CSS content is missing.
A common problem players may face is CSS content being missing.
Thankfully, we have an option for that.
Download CSS from here: https://downloads.warzone.gg/CSS.zip
Once downloaded, go to your Garry's Mod install directory
Go to "addons"
Create a folder called "css"
Open the ZIP file, navigate to the "CSS" folder inside of the ZIP and then copy all the folders (maps,materials,models etc) to the "css" addon folder you created.