% Define the keys used in output attribute matching.
/.outputattrkeys [
/OutputType /Duplex /Tumble /ManualFeed
] readonly def
} ifelse
Remove the "/Duplex /Tumble /ManualFeed" after "/OutputType" and save the file.
Now undo everything which you edited in the PPD files (Reactivate '*cupsFilter: "application/vnd.cups-pdf 0 foomatic-rip"' line) and restart CUPS so that the manual changes in the PPD files get active. Now try to print again. Does Duplex work now?
I do not know whether it helps, but can you try the following:
Do
sudo gedit /usr/share/ ghostscript/ 8.64/Resource/ Init/gs_ setpd.ps
and look for this structure around line 424:
% Define the keys used in output attribute matching.
/.outputattrkeys [
/OutputType /Duplex /Tumble /ManualFeed
] readonly def
} ifelse
Remove the "/Duplex /Tumble /ManualFeed" after "/OutputType" and save the file.
Now undo everything which you edited in the PPD files (Reactivate '*cupsFilter: "application/ vnd.cups- pdf 0 foomatic-rip"' line) and restart CUPS so that the manual changes in the PPD files get active. Now try to print again. Does Duplex work now?