Hi guys, i am not able to launch l4d demo from steam. I get a message the steam ticket has expired and prompts me to renter my password. I continue to get the same message every time i launch it from steam. I played the demo in the morning. It was working well. I am still able to run it from the steam folder. Any idea as to what is wrong? And this is happening only with the demo and not with any of my other steam games. Please help me out. Thanks.