Q: Updated to OS X El Capitan and printer is now offline

Go to the manufacturer's tech support site and see about an updated driver or other solution. Since Apple does not make printer drivers there isn't any help they can provide.

Check Printer & scanner software available for download for your Mac to be sure you have the current driver installed.

Printers not behaving? Reset them and start from scratch | MacIssues

OS X Mavericks- Set up a printer - should still apply.

I have this problem too. When I reset the printing system, my two printers are no longer visible in the printer list. When I click "+" I see one of the printers. I select it and it begins to configure. After a couple of minutes it fails and reports that the computer is "unable to communicate with the printer at this time." Odd, considering that the printer is listed.

Thoughts?

I had to buy a new printer in the end, as there is no new driver for my old Lexmark, and Lexmark say there will not be one. It was quite old, but I liked it!