Garry's mod not launching at all

Hello everyone. Since yesterday, my Gmod isn’t launching any more. When I click play, my pc is loading something for a few seconds, it tells my Steam friends that I’m playing Gmod, nothing pops up at all and then it says I’m not playing any games.

I restarted Steam, I restarted my computer, I unsubscribed to every addons I had, I verified the game cache, I verified every Valve game’s cache (so that includes TF2), I’ve uninstalled Garry’s mod and reinstalled it, deleted the game folder and downloaded it again (twice), nothing changes. You may ask what happened between the last time I played Gmod (2 days ago) and when it stopped working (yesterday), it’s simple : I bought Rust and played it for a few hours, nothing else.

Thanks in advance to anyone who’ll be able to help me.

What is your antivirus, what exactly is happening and can you attach a video of it?

Have you tried restarting your PC?

My antivirus is Symantec Endpoint Protection. I tried disabling it but it didn’t change anything. I said I restarted my PC.

There’s nothing really to record : the hl2.exe process starts running, and then stops itself after a few seconds. I don’t get any error message.

Glad to see someone else having the same problem. :slight_smile:

[editline]30th October 2014[/editline]

Found a fix! Rename or delete your Team Fortress 2 folder.

Source: http://forum.facepunch.com/showthread.php?t=1434324

Unfortunately I have tried this and it still doesn’t work.

A quick update on this : I managed to make the game launch twice today, right after a TF2 update. The 3rd time I tried, it did the same thing again though, and now I can’t launch it any more…

End of the story : I couldn’t launch any Valve games while Mumble was running… Thanks for the help.