Sometime the end haven't create anything

I create a new 15w31c world , then go to the end , it have nothing at the end, well maybe it's just haven't finish the loading , so I wait.... but after 5min , it's also nothing here , you can't move , just stay at x100 y49 z0 , and no any block here , it have enderdragon bar , but you can't see a enderdragon. Then, I try to tp to another position, then you can move now, but , you can't find where is the enderdragon and the EnderCrystal ...

Well , I try to open another world and go to the end , it have building , enderdragon , everything just fine , so I think this issue will happen sometime not always.

Well , I also try 15w31a , it have a same problem.