When it says it's out of paper, but clearly isn't, see...
Most of this is silly and tedious.
"In case anyone has the same problem in the future... My husband found a wheel
near the roller hinge, turned it forward a few turns & the roller lowered
back down to where it belonged. A simple enough fix, but after almost 3 hours
on the phone, HP TECH SUPPORT refused to tell me how to do it! They wanted me
to pay them for the info... [it wasn't in the manual either]"
Performing #2 would be a good opportunity to look for and try this suggestion,
but be gentle and don't go forcing random rollers or wheels to turn that don't
seem to want to.