Hello John
one of my c5790 machines did a auto firmware update (16.62.CV20J9) and its not downgradeable.
İ tried to put your firmware ( CV14I9 ) many times but its not working. Printer doesnt accept your firmware anymore.
İ bought many licences from you and i know how to do it. Also tried in regular mode. Firmware upgrade is not allowed in regular mode.
Pic. shows after finishing of CV14I9 firmware upgrade at program update mode.
Do you have any solution for this new firmware??