I just re-opened my ticket about the issue from earlier. Maybe you should do the same. When I first got a response to the ticket, I was able to play for a short bit of time before being kicked off again, so GMs can disable the block somehow (I thought it was because I ended up in a glitchy spot falling off a flight path, so I got a GM to move me to Durotar, and the WOW51900328 issue disappeared for 30 minutes).