Thank you for answering my questions. If this happens on two different computers and you are unable to reset the print settings within Printing Preferences, try restoring the printer to factory defaults. This will remove it from the network so you will have to set that back up again.
--Restoring Factory Defaults--
Complete this step and try printing again. If that does not work, have you tried uninstalling the software and re-installing it? I am curious as normally this would only affect one computer not both.
Just for clarification: what do you mean by upgrade when referring to your computers?