Hopefully this helps troubleshoot it some more: I noticed that even when I use my old authkey file to play the full game, the Steam Authentication notice in the upper left still says Failed. This also applies to all 3 of my friends I have played with this week on Steam. We were all able to sucessful...

Basically, it looks like whatever Introversion did last May that fixed this issue for myself and others, needs to be done again.

Hello, Just thought id add to the issues here. New build on windows on a new build PC. Downloaded Steam and Defcon and I'm getting the same error. Deleted auth key once started up as a demo user and still getting the same problem. Awesome game, but to be honest, I paid for it and i'd like to play t...

Those of you experiencing this problem, could you please do a test for us? We may have a temporary workaround. - Go to your Steam Defcon folder (something like H:\games\Steam\steamapps\common\defcon), and delete the authkey file - Run defcon in steam - You should see the Steam authentication dialog...

Just so I'm clear; this update has not been released yet, right? Because there's a growing number of us that just recently purchased DEFCON on Steam but can't play due to the AuthKey issues (http://forums.introversion.co.uk/defcon/viewtopic.php?t=7256)

I filled out the contact form on IV's site, and sent them a note to their twitter feed.

I feel bad cuz i convinced a friend to buy the game with me yesterday, and now we are both out $10. =/

The last Steam Support response just told me to talk to Introversion. They can't help me.

This is what I get in the Debug log after a fresh uninstall/reinstall/run: Defcon 1.43 steam built Jul 2 2007 Parsing archive main.dat...DONE WinSock started Client listening on port 5011 Parsing Coastline data (1776 islands) : 51ms Parsing International data (2753 islands) : 23ms Pa...

I am sorry for adding to an already extensive list... But I am having the same problem with authentication keys, I bought this game a day ago on the 13th May through steam and I have tried all of the solutions posted here to no avail. I understand that the authentication servers go down from time t...