The Update Server for World of Tanks is will be undergoing maintenance on the 21st February starting at 09:00 CET (08:00 GMT). This maintenance is expected to last for 1.5 hours.
During the time, the update service for World of Tanks will be unavailable. If you already have the latest version of the client, this will not affect you and you’ll still be able to play as normal. If you have yet to update your client to the latest version (8.3), you’ll need to wait until the maintenance of over before you can play.