Critical error on loading of Shrine of seven kingdoms

I hearthstoned back to the MoP alliance world. This happens, I cannot login my character anymore.

http://imgur.com/8WSFJn3

This is a bug that affects all MoP private servers and tends to effect Orgrimmar, Stormwind and Vale the most. In my experience, it's always gone away at, on most, the fifth or sixth login try. It very rarely happens at all outside of those 3 cities, which I try to avoid.

I guess it's hard to avoid the Vale since it's the portal location. Maybe set your hearthstone to the inn closest to the Vale in Pandaria and if you need to risk going to the portal location (as opposed to Pandaria itself) you can fly over to the Vale.