L4D and L4D2 Content Won't Mount.

I’m having an issue with my server, where I’ve installed L4D1 &2 content on the server and client, and the props do appear on the server but none of them have physics. The props work in singleplayer but not my server.

Then you didn’t install it correctly

I used my server control panel to install it.

in the case of Left 4 Dead 2, isn’t that game currently not on the mount list anyway?

I’ve also tried mounting without L4D2.