I has the exact same problem, contacted WOT, sent in a ticket and this is their reply:
Please try to delete the World of Tanks temporary files as described below:
- close the game;
- download the following archive:
http://dl-support.wargaming.net/wot/ru/updates/wot_pref_en.zip
- unpack the .bat-file from the archive to any folder and run it.
Please note that after you run this file, the in-game settings will be reset.
Let me know it goes