Make sure your paper guides are snug against the edges of the paper while the paper is loaded in the tray. There should be little knotches in the tray to help you confirm the guides are clicked into the correct position.
Otherwise if you are referring to the document feeder then manual adjustment may be the best thing you can do. AutoDocFeeders normally do not lock into position and frequently need to be messed with on many printer models. Sometimes a little habbit building can resolve a problem like this. If not you can try to contact HP for support since this is such a new printer. However, unless you can proove there is a mechanical defect on the tray or feeder there isnt likely anything they can do.
You do have something with the No Paper message though. Even if the guides are off the printer should recogonize there is paper loaded in one way or another. Paper guide issues normally result in size mismatches as opposed to no paper errors.
