If there is a paper jam in the multi-purpose tray, follow these steps:
Press the cover release button and then open the front cover of the printer.
Take out the drum unit assembly (drum unit with the toner cartridge).
Remove the paper from the multi-purpose tray.
Fan the paper stack, then put it back in the multi-purpose tray.
When loading paper in the multi-purpose tray, make sure it touches the back of the tray and stays below the maximum paper mark.
Open the front cover of the printer and close it, or press Go to start printing.