I went to log out on this character, Scheibe, earlier today. Instead of the game closing, it acted as if I disconnected. Now when I try to log into this character, I either get stuck on the loading screen or reverts me back to the Character selection screen and says "Character Not Found" even though he is clearly on my character list.
Try logging in from a different character, usually that will force the stuck character offline.
Everytime it loads to about 90% and gets stuck. I just tried logging in on my friends computer too and it did the same exact thing.
Ring Blizzard support, they've always been extremely helpful when I've had problems. Though the wait is sometimes a little long.