OPERATING SYSTEM IS SEQUOIA 15.4.1
Macbook Air
HP OficeJet Pro 6978 All-in-One Printer.
Message rec'd upon print attempt: "The printer may be out of ink."
"Device Status Unknown."
"Stopped, Filter, Failed."
Changed cartridges - all full.
Able to copy/scan/print test pages.
Unable to print.
Thank you!