Brief post from WG support:
We are happy to announce the update of World of Tanks to version 9.22.
Due to updates, World of Tanks servers will be unavailable on 07/02/2018 from 01:30 CET to 08:00 CET.
In addition, therefore:
The clan portal (eu.wargaming.net/clans) will be unavailable from 01:30 CEST 07.02.2018 to 08:00 CET 07/02/2018
Thank you for understanding,