certain titles not mounting anymore. picture included

i have age of chivalry, and dystopia installed, games that usually would mount right on to garrys mod, and were working fine a week ago. however they are no longer mounting, although counter strike source in mounting just fine. here is a picture of what i am seeing. as you can tell, the games i dont have are marked with an X. the games i have installed, but arent mounting are marked with a picture of a file, and a red circle. like age of chivalry. how can i solve this? (i have tried all the basic methods of troubleshooting. uninstalling all of them, and reinstalling Etc.)


All those games cannot be mounted because the developers have not updated to Valve’s new content system. Not a problem with Garry’s Mod.

does this mean those games are no longer compatible? and will never mount again?

Until their developers decide to update their games.