Tomorrow, on 10th April 2013 at 06:00 CEST (GMT +2) the game server will undergo short maintenance. This should last approximately for 30 minutes and during this period of time you won’t be able to connect to the game.
Once the maintenance is over, you will need to download a small patch (32.6 MB). This will be done automatically by the launcher. Please note that other services such as the support server, forums and official website will be running as usual.
Thank you for your understanding.