l4d2 doesn't show on gmod 13

[llpanic]

the game doesn't show in the list of games you can mark you have only l4d is in there and i can't mark it, why is this?

thanks for your help

[Dgames101]

i dont know why but gmod 13 doesn't even try to find l4d2 files. Its not in the game detection system. You could do a manual install but that can be glitchy and the ragdolls will be missing a limb or two cause gmod isnt good with reading l4d's files due to the fact the games run on a slightly modified source engine.

[MattJeanes]

This is intentional as L4D2 and Portal 2 have moved to the 'SteamPipe' system and until GMod moves to it, mounting the games is difficult.