The host IP is listed along with some ports.

Follow the procedure below.

  1. Uninstall the game client.
  2. Go to: %APPDATA%/../Roaming/TankiOnline
  3. Delete "Local Store" folder.
  4. Re-install the game client.

Tell me if it helps.

Are you suffering the same problem on the browser version too? If no I would suggest you to enter the game using google chrome or standalone flash player.