This is an ID that is already logged in...

Could mean that you were auto banned. Where was the last place you were?

It's not an autoban. It's just a really bad glitch. It happened to my friend when I was on certain somebody's account training at Galloperas. He was randomly disconnected as soon as he hit level 109 and he couldn't log in until after the server check. Lucky for him, the server check was only 5 hours after his account was stuck.