HP OfficeJet Pro 8720 will not print full duplex on Mac w/ Fire Fox Quantum
I called HP Tech Support to resolve an issue with Firefox Quantum printing full duplex using HP OfficeJet Pro 8720. The glitch with Firefox and only Firefox is that it selects "Index Card Letter 8.5x11in. HP Tech Support stated that the glitch with Firefox is that the printer setting should be "US Letter." I do not have this problem using Google Chrome of Apple Safari. Please get this corrected as soon as possible.
Todas as respostas (2)
Try : https://support.mozilla.org/en-US/kb/fix-printing-problems-firefox http://kb.mozillazine.org/Problems_printing_web_pages
If does not work : uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files and C:\Program Files(x86) Then restart system. Note: your Firefox Profile is saved. But you should make a back up before you do : https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
Reinstall with Current Release Firefox 57.0.2 with a Full Version Installer https://www.mozilla.org/firefox/all/
Please let us know if this solved your issue or if need further assistance.
Your solution is for Windows-operated PCs but not for Macs.