I may have found a fix to this error at least til the DEV team can perminatly fix the problem. If you get this Error go to create new char, make a new char, (don't worry about looks and all that since it won't be saved) when you get to the screen that lets you select world exit out to the char select screen and try to log in again with your main char. I did this twice and it worked each time. It's a FFXI fix to a FFXIV problem and it really seems to "fix" it on the player side. You may still encounter this error until SE can fix it on their side so if you log out again and try to log back in and get this same error, repeat the steps mentioned above and you should be able to get in.