1. Play a character until he has nearly everything the game has to offer at the moment.
2. Disconnect from the server and close the game via the "close" button in the game menu.
3. Start the game.
4. Use the "play" button after the game menu is visible. The avatar next to the game menu wasn't visible at this time (black background).
5. Choose a server and join it. The avatar was still not visible at this time I suppose.
6. Receive the message from above and lose all progress.