@TechConnectify
The error occurs if the printer says "something is wrong, but I have paper" - possibly a paper jam.
Nobody is sure whether this was actually possible, but it was thought that a high-speed impact printer, given a long enough paper jam, could actually set the paper on fire. The hope was that "printer on fire" would inspire the user to actually check on the printer - likely in a different room at this point - rather than sit and hope the operators take care of it.