I will guess that there is a sensor jammed/clogged such that it believes there is something in the pathway that it tries to reject - spits out a piece of paper. When that sensor does not clear, it shuts down. Have you cleaned the optical sensors? Either 91% Isopropyl alcohol and a very soft cloth, or distilled water and that same cloth.

Paper dust is is a very real issue, especially on heavily used copiers. Best of luck with it.

Peter Wieck
Melrose Park, PA