I was just playing through, and I had a new quest in Windhelm, where I had to talk to a guy called Johral or something like that, and he told me of a dragon in Bonestrewn Crest. I went there, and I swear my game just practically blew up.
The dragon was flying backwards, there was immense lag, the dragon's unkillable, I'm afraid that all dragons are going to be like this in my version and I don't want to re-restart.
So is this a bug with the new patch, or is this common?