I recommended a mate grab DEFCON and he was faced with this issue where Steam Authentication is attempted, but fails. I luckily already have my authkey, but the message still appears in the top-left corner of the main menu. Removing the Authkey results in both failure to get Steam Auth, and Game auth.
This is my debug.txt:
Defcon 1.61 STEAM built Dec 1 2011
Parsing archive main.dat...DONE
Found language 'english' with caption 'English' in 'data/language/english.txt'
Found language 'french' with caption 'Français' in 'data/language/french.txt'
Found language 'german' with caption 'Deutsch' in 'data/language/german.txt'
Found language 'italian' with caption 'Italiano' in 'data/language/italian.txt'
Found language 'spanish' with caption 'Español' in 'data/language/spanish.txt'
Client listening on port 5011
Parsing Coastline data (1776 islands) : 21ms
Parsing International data (2753 islands) : 8ms
Parsing City data (2745 cities) : 10ms
Parsing archive sounds.dat...DONE
Authentication key set : 'STEAMR-ICLIYM-PYTSMV-OVPNJU-VOF'
Connection established to MetaServer on port 5008. Listening on Port 5009
Steam Authentication Initiated
Steam Authentication : Logging On To Steam
Steam Authentication : Getting Steam Id
Requesting data from MetaServer : LatestVersion
Requesting data from MetaServer : MOTD
Steam Authentication : SteamID = ID WITHHELD
Steam Authentication : Getting Steam3 Auth
Steam Authentication : Requesting Authentication
Received data from MetaServer : LatestVersion
Received data from MetaServer : MOTD
Requesting authentication of key STEAM*-KEY-WITHHELD
Received Authentication : STEAM*-KEY-WITHHELD : (keyID 9172546) : Accepted
Authentication HashToken set to HASHTOKENWITHHELD
Requesting data from MetaServer : UpdateURL
Received data from MetaServer : UpdateURL
Steam Authentication FAILED
CLIENT : Disconnected
Disconnected from MetaServer
This issue is also being reported on the Steam-based forums here: http://steamcommunity.com/app/1520/disc ... 923072570/
Cheers, and I look forward to being able to play with my mate soon