Epson EPL-N1600 Reference Manual page 147

Duplex Mem Overflow
There is not enough memory to print both sides of the document
using the duplex unit. To correct the error, press the Continue
button on the control panel. If the message remains, reset the
printer as described in "Reset", on page 6-29. You may also be able
to clear this message by turning the printer off, waiting 10
seconds, and then turning it back on.
If you continue to receive this message when printing a particular
page, try simplifying the page by limiting the number of graphics
or reducing the number and size of fonts.
You can also add more memory to the printer as described in
Chapter 3, "Options".
Duplex print was off
An attempt has been made to use the duplex unit, but the correct
setting has not been made..
Duplex Unit Fail
The duplex unit is not working correctly. Check the installation
of the unit.
Exiting Paper Jam
Paper is jammed in the printer. See "Paper jammed at the paper
exit", on page 6-8 for details about removing jams from in the
printer.
Troubleshooting and Maintenance
6
6-21