I receive Game Error: Failed to Contact Key Server when launching a game from Steam.
This error most often occurs when there is a communication problem between the computer and the Steam network. Even if browsing the Internet has no issues, there may be an issue or program blocking Steam functionality.
Upon trying to launch a third-party title on Steam, you may experience this error. The most common causes of this issue are listed below:
While we do our best to anticipate demand from our users, occasionally we may run out of keys to provide for your purchase. When we are out of keys, this error will appear. You will be issued a key as soon as we have been given more by the game's publisher.
If you are trying to run the game, or view the CD Key for a game, while using an operating system on which the game has not been released (i.e. attempting to run a Windows-only release while using the Mac OS X Steam client), then you may receive this error. To determine which operating systems a title is available on, please see the Steam store page for information.
Some third-party games may require the opening of additional ports on your router in order to work correctly. We recommend following the Using a Router with Steam guide for initial troubleshooting.
Your firewall might be preventing the game from working correctly. We recommend following the Using a Firewall with Steam guide for initial troubleshooting.
If this problem occurred directly after a Steam update and the firewall is already disabled, please try this process:
If you are currently experiencing intermittent connection problems, you may also experience this error. Please contact your Internet Service Provider to make sure there are no current outages in service at this time.