Wont let me play!

[DjBreadStick]

Ive downloaded the game, i can see it in my Steam library, but when i go to click play nothing happens. Please help?

[Boxy]

Make sure you have got the Source SDK, Source SDK Base 2006 and Source SDK Base 2007 installed (a whopping 6GB or so), it needs these to run, it's not 'standalone'.

[DjBreadStick]

You legend, thank you very much for the help!

[DjBreadStick]

I have now bumped into another problem. When i try and join a server it says i have signed into another computer so i need to sign in again. When i do it says i need to sign in again and just keeps repeating itself.

[Sniper]

Sounds like someone else is using your account, change your password.

[DjBreadStick]

Something to do with expired tickets.