Steam: no connection to the keyserver - what to do?

If you get the message "A connection to the keyserver could not be established" when starting a Steam game, there can be several reasons. Here you will find the most common causes and the corresponding solutions.

No connection to the Steam key server: these are the causes

• In most cases, the problem occurs when there are not enough keys available for a game. This can happen especially in the case of discount campaigns when many customers buy a certain game. As soon as new keys are available, the key will automatically be added to your Steam account.
• An incorrect Steam update can also be the cause. To solve the problem, first close the Steam client completely. Then change to the program directory (usually C: \ Program Files (x86) \ Steam). There you delete the file "ClientRegistry.blob" and start Steam again.
• If you try to start a game on an unsuitable operating system, the error message may also appear. This can be the case, for example, if you want to start a game that is only suitable for Windows via the Steam client in Mac OS X.
• Check if your firewall is blocking Steam. The files "steaminstall.exe", "steam.exe", "hl.exe", "hl2.exe" and "steamTmp.exe" must not be blocked. You can find help with the configuration in the practical tip "Where can I find the firewall settings?".
• Some games use certain ports that must be enabled in your router. You can find out how to do this in the practical tip "Enable ports - how does it work?".
• Problems with the Internet connection can also trigger the error message. This can be a temporary technical malfunction. If the connection problems persist for a longer period of time, you should contact your Internet provider.

There are often connection problems on Steam.