1. Check if any objects are blocking the bypass tray or the path to the printer.
2. Make sure that the paper tray is properly aligned and loaded correctly with paper.
3. Check if the paper size setting is in accordance with the size of the paper that is loaded in the bypass tray.
4. Make sure that there are no wrinkles on the paper.
5. Ensure that the lock lever that holds the bypass tray is in the unlocked position and that the bypass tray is not too full.
6. If the problem persists, follow the printer manual to find further details.