Recently installed Catalina on my iMac and now I cannot print anything.

[VirginiaBar]

I recently installed Catalina on my iMac and now cannot print anything from my HP Laserjet Pro MFPM127fw or my Laserjet Pro 200 Colour M251nw. Error message is "stopped can't open/private/VAR/spool/cups/tmp/003455f9787f6 could not be opened". Have tried redownloading drivers with no success. Phoned up Apple helpline and they suggested that it's a problem with the printers and need to contact HP.

[BryanCustomPure · Accepted solution]

The solution is to download (and install) this package (From HP FTP) which will update drivers AND THE CERTIFICATE:
ftp://ftp.hp.com/pub/softlib/software12/HP_Quick_Start/osx/Installations/Essentials/hp-printer-essen...
The install takes a bit. Let it run, even if it seems like it stalled out!

It is NOT the same as the driver package, Easy Start, or Easy Admin other people are recommending.

If the link comes up blank, try right clicking and saving it. If you install this package and still have trouble, try restarting. Then go about uninstalling your printer and reinstalling USING THIS METHOD ONLY: Apple Logo (Upper Left of Screen)/System Preferences/Printers & Scanners. Then restart your computer. 

If you still can't find the printer, install the 5.1 driver package from HP: https://support.apple.com/kb/dl1888?locale=en_US

Then restart and try to install again through the Printers & Scanners menu.

Easy Admin did nothing. Easy Startup did nothing. 5.1 drivers did nothing. This worked for me!

If this solved your issue, please thumbs up and mark as solved!

[VirginiaBar]

Absolutely brilliant - thank you! It's now working perfectly!