Please check the link. => http://img517.imageshack.us/img517/230/asdfgdfhhj.jpg
Yesterday my game was fine.Today I got that error.After I click "OK" the updater closes.
i believe there is a simillar topic with this problem in 5x-General Discussion section.if you want to play you can rename/delete updater for the time being and enter game via l2.exe in system folder