HP Printer not Printing.....

Hi Because I have another computer that isn't using Mojave or Catalina I was able to print to my Hp laser printer CP2025nt from the other computer as the HP is a networked printer. When the old 2008 Mac Pro is up and running the sharing on the 2008, preferences puts that printer on the network and it shows up in the "printers & scanners" in system preferences of my Mojave computer. And now I can again print. So I guess it's good to have more than one computer (old or not) And more than one operating system(old or not).

Apologies for the long winded expiation.

Do not feel alone here, there is currently a HP issue...

https://h30434.www3.hp.com/t5/Printer-Setup-Software-Drivers/HP-Utility-fails-with-Code-Signature-Invalid-MacOS-10-15-7/td-p/7823883/highlight/true

HP's security certificate has expired. Search HP for a resolve here.

Your Mac has encountered an expired security certificates.

The fix for me was simple... once you know what to do! A few days ago, an error message popped up on my iMac. "HPDeviceMonitoring.framework" will damage your computer, it said. I assumed it was fake. It's not. It's your computer doing its job. It popped up every time I booted up. The problem that it doesn't tell you what to do. Then a few days later I tried to print on my HP Office Jet Pro and it was halted after loading to the printer with "Printing - Can't open '/private/var/spool/cups/tmp/ some long number ending in ccf'. Then I called Apple Cares. Excellent woman told me to dump the file that the error message directed me to in Finder. That's it. Everything works. So: if you get the error message, hit the "Show in Finder" button, which will take you to the file... and grab the entire file and trash it. In my case, the errant file is identified above.