I recently did two horde death knights, purely to have access to the neutral auction house.
For transfering gold from alliance side to horde side, for a new warlock team.

The Death Knight player frame (and party frame if the party member is a DK) is not visible.
Well it is a square of shaded text the right size, but there's nothing in the frame.

With a mixed party, everyone else shows up fine.
And you can click on the shaded frame, and the target frame goes shaded too.

I'm guessing it doesn't like having the runes attached to the frame or something.
But am not sure.
Not sure if my version of Pitbull is the newest, but DK's had been out for a long time when I downloaded it.

Anyone else have anything like this?