The paper guides are not set correctly.

Make sure that the paper guides in the lower cassette are set in the correct paper source in your application.

The paper source setting may not be corrects.

Make sure that you have selected the correct paper source in your application.

There may be no paper in the cassette.

Load paper.

Too many sheets may be loaded in the MP tray or lower cassette.

Make sure that you have not tried to load too many sheets of paper. For the maximum paper capacity for each paper source, see Paper Sources.

The paper being printed on is shorter than the paper size set in the printer driver.

Load the correct size paper, and open and close the cover to cancel the error. Alternatively, cancel the print data, and open and close the cover to cancel the error.