There seems to be some problems with the new profile support I guess. After a profile reset and an interface reload I can see the manabar, but after joining bgs for example the bar disappears and cannot be reenabled until a new rest + reload.
I switched back to r48040 and everything is working as usual, so it seems not be an issue with patch 2.2
edit: gnah, same problem again. it worked for some time and now manabar is gone again :(