Lexmark MS822
650.84 error message is prompted on the printer control panel when printing in duplex.
Turn off the printer for at least a minute and turn it back on again.
Print a document in duplex and check if the error message still appears.
If the issue remains, restart the print job.
Contact Lexmark support if this issue still occurs after second duplex test print.
The printer displays any of these error codes on the control panel: 43.40P, 43.40Q, 43.40R, 43.40S, 43.40T, 43.40U, 43.40V, 43.40W, 43.40X, 43.40Y or 43.40Z
An “Invalid Engine Code” error message indicates a problem with one of the internal operating programs of the printer. The printer is not able to receive, and process print jobs until the printer is reset.