Someone has sent a print job from a computer to the copier with an odd paper size specified. Go to Job status, under "print" highlight the first job in the que and delete it. (if the job was sent more than once you will have to repeat. ) Check the document and print settings of the offending document.
You probably have a paper jam in the auto feed unit. Open the auto feed and check for bunched up paper and if you don't find any open the side doors and check for paper jams there. Let me know what you find.
Pull the paper tray to the front, after it is stuck pull it up ward and front
In the printing properties, on the paper select tab, change the paper tray from automatic to by pass tray
Sounds like a sensor on the exit section has failed if the copier is coming up with that message and the tray is empty. Had the same problem on a mx-3110...
Please verify that no printer paper is jammed or partially fed into the printer. If you have one or more pieces of paper stuck in the printer these will need to be manually removed before the printer will print again.