Hmm, that be very strange. Ye say 'tis on every character on the one account but the other works fine on said computer? 'Ave ye tried making a new character on the account that is 'aving the issue? Ye 'aven't been banned, 'ave ye? We aren't supposed to speak of bans, but if ye were, this could be why ye cannot log into the game on that account.
It could just be that ye need to send y'er characters home. Doing this sends ye to Lonely Cave by default, or the selected spot that ye may 'ave set y'er home to. Head up to the top right hand corner of the site and log in. Then, head to y'er User Panel, select a character and send it home. Try logging into the account and play on the character ye sent home. Let me know if this fixes y'er issue!
Other than that, it could be a server glitch.
