Printer issues after installing Mojave

*Potential fix for HP Printers:*

I had a similar issue with an old (circa 2005) HP printer and a 2015 Macbook Pro:

• After installing Mohave, my printer no longer responded when I sent items to print.
• When I removed the printer from Printer Settings (System Prefs --> Printers --> clicking the "-" button) and then tried to add it (clicking the "+"), my Mac wasn't finding the printer at all; nothing was appearing in the list of printers.

Here's how I fixed it:

• Download HP printer driver v5.1: https://support.apple.com/kb/DL1888?viewlocale=en_US&locale=en_US
• Remove the printer if you haven't already (as described above, using the "-" button in printer settings)
• If connected via USB, unplug USB cable from Mac and power-off printer, and then reconnect USB and power-on printer (crucial for me - wasn't working until I did this)
• At this point, the printer reappeared in the list of printers, and I could install it following the standard Mac process (click "+" button, select appropriate drivers etc. Printing works as usual :) !

Good luck!

Editing the permissions on the cups config file and then reinstalling the printers using only a generic postscript driver worked for me on two different laptops and a new Mac mini, restoring the ability to print to a routed printer using IP printing. Not ideal, but workable.

The other alternative is to roll back to High Sierra.

John,

See my other post on this topic. “Reset the printing system” on the client laptop fixed the problem right away. At least for our specific problem with shared printing (not AirPrint). It’s in the published instructions.

Ron

This is a guess, but it's possible the system is spinning when trying to load the vendor drivers.

One thing to try:

1) add another printer with the Generic PostScript PPD in AddPrinter

2) make that your default printer

3) launch an app, see if you can reach the print dialog.

If so, see if you can now switch to the Epson driver.

Hope this helps.

I'm beginning to grasp that Mojave has really upped the game with its "Library Validation" requirements. I haven't seen it explained in plain-speak but, I suspect that print drivers that do not use Library Validation are sand-boxed and not allowed direct access into the applications. Something like a CUPS equivalent driver is used in place of the older unsecured driver. It appears that things began to quietly ratchet up in 10.13 with regard to Applications that used Library Validation such as Safari, Pages, Numbers and Microsoft Office. I see the same driver when I used those applications as I see in all applications in Mojave. Other apps in 10.13 such as Notes and TextEdit gave me full access to my driver. Now, I suspect that as the driver itself is old and does not use Library Validation, its not being used at all.

Bottom Line: Get your printer manufacture to write a new Mac OS 10.14 Compatible Driver!

Sorry for any inaccuracies above, super smart codey people. I'm sure you'll get it better than I do. I just want to print again.

There are many posts of "solutions" that do offer limited relief in some situations. But none of the proposed solutions fix the fundamental defects in the Mojave printing system and provide a STABLE solution for all methods of printing (Bonjour, IPP, Windows Spooling) to print to all printers, especially if they or their print spoolers are on different routed subnets other than the local subnet with the user's workstation.

See Apple Bug 46807004: https://bugreport.apple.com/web/?problemID=46807004

Agree. You are correct in your assessment. Nothing we can do can fix this flaw in Mojave. I have been an Apple user since the 1980's. Printing has always been a core capability; IP printing has been a capability since TCP/IP became popular in the 1990's. Mojave broke routed IP printing. While there are some TEMPORARY PARTIAL work-arounds, there can be no solution until Apple fixes the defect. Options are:

1. Roll back to High Sierra
2. Open a ticket with Apple. Yes they do respond. Even if they can't fix it, it may get their attention.
3. Do the CUPS edit described above to fix the permissions issue, and select only Generic Postscript drivers, or just be on the same subnet as your printer.

None of these are a good solution. Sorry.

The problem is solely with Print Explosion. It is a 32bit software and that is the problem. They have had plenty of time to upgrade their software to 64bit and they haven't. The new Hallmark software says it works with Mojave and I will try that after taxes.....If you want to keep using Print Explosion you can create the card and print to PDF (save and before you print the second to pdf, change the name or it will overwrite the first pdf print). A friend of mine has no problem creating the card and just needed some info on how to save and print it out. This is working for her, give it a try and see.

I suggest opening a support case with Apple. I did this recently and was pleasantly surprised with their prompt response and ability to view my screens and provide me with graphical guidance on the screen that quickly resolved my issue. There was no need to go to the Apple Store or do anything complicated or unnecessary. This will also register the Mojave issues with the Apple developers that might result in a quicker release of a software update fixing the underlying issue.

Sorry for the ongoing frustrations we are all sharing.

I tried that, it didn’t work for me. I can only print if I connect via Ethernet or if I move my laptop to where the printer is, disconnect from the WiFi then reconnect so I’m connected through the same pod then I can print. It is seriously annoying.

OK - found out how to get to it. Ignore previous post. If anyone else is searching for this cups.conf file: Go to Finder>Go>Go to Folder> "/private/etc/cups/cupsd.conf"

But it has still not fixed the problem. EXCEPT: when I try to print, it shows the document going to the printer and then it disappears from the printer proxy screen, as if it had been printed. But nothing comes out of the printer. Have rebooted the printer, disconnected & reconnected the ethernet cable, deleted the printer (for the umpteenth time) and reinstalled it (again for the umpteenth time).

I'm going to start a support ticket to add weight to (hopefully) force Apple to do something about this.

My problem was that the the computer would find the printer but every time I tried to print the yellow light came on telling me the printer was busy. I contacted Brother and Apple both were helpful with the normal advice but the issue was not resolved. The printer however, printed from my laptop even though the desktop had issues. I copied the old Brother software from the liberty > printer folder and pasted into the the desktop folder. This worked, the issue was that Brother no longer supported my particular printer. I checked the Brother web site and it did state this but it took some looking and their techs did not seem to know this. Hope this helps anyone with a similar issue. Cheers JohnBrom

What I have seen with other vendor drivers, now that most Apple apps have Library Validation in Mojave, is that the vendor settings are all placed in the Printer Features panel. Maybe they are named differently? With a few exceptions, the functionality shouldn't be gone.

This worked.

10-10-2018 10:04 PM - edited 10-16-2018 10:16 PM

You're right that Library Validation has been increased in Mojave, but you should find the vendor settings in the Printer Features PDE. Some of these features don't seem to work correctly, again because of Library Validation. Most Apple apps have the increased Library Validation; but the non-Apple apps should at least appear as they did on 10.13.