ok, so I was messing around with shape keys and custom bones and everything was working fine. Then, when I started using the pose library it was causing bones to disappear.
The lips have custom bone objects:
I clicked the “Apply specific Pose Library pose to the rig” button (circle in green)
And now the lip bones are missing.
Alt + H didn’t bring them back and yes, x.ray is on. The bones are visible in edit mode and though they are invisible in pose mode, I can still select them if I click over where they should be. So, I guess they’re there, but they are invisible.
My question is, is this a glich/bug or am I overlooking something? Has anyone else experienced this?
The last bug I reported was not actually a bug, I just didn’t know how to use the fire simulator, 
so I thought I’d post on the forum first this time.