Ensure that the printer's touch screen does not have resin, dust, or other debris on it. If it does, pour >90% alcohol solvent on a nonabrasive cloth and wipe the screen down.
Ensure that the QR-Code Scanner's window does not have resin, dust, or other debris on it. If it does, pour >90% alcohol solvent on a nonabrasive cloth and wipe the screen down. You will not have access to clean behind the scanner's window. If you see that resin and/or debris has gotten inside the scanner window, contact your reseller.