HP Photosmart C4480 printing problem in Mac OS 10.15.7

This same message came up on the same day (Oct 23, 2020) with a different model HP LaserJet printer, and I've found many people posting to the HP website: same message, same day, same problem. We're using Mojave, but it seems to be that someone decided to not support older printers any longer. HP driver software (latest I can download) won't work with Mojave, nor does Mac's printer software seem to work. Delete/reset printing system/re-add all seem to initially work until it comes time to print. The printer acts as if there's a previous print-job in queue (though nothing there) along with the same error message as yours.

I have exactly the same problem, with a different HP printer, HP Deskjet 6980, and on two computers, a MacBook Air running Mojave 10.14.6 and a very new MacBook Pro running Catalina 10.15.7. The problem appeared literally overnight, I had changed nothing. Downloading and reinstalling the driver software does not help.

Please have a look at this contribution:

https://h30434.www3.hp.com/t5/Printing-Errors-or-Lights-Stuck-Print-Jobs/Driver-Certificate-Expired-Yesterday/m-p/7826768/highlight/false#M895582

For me, it has solved the problem.

The problem is the HP Printer Driver Certificate has expired. A programmer within HP has posted an ftp link to a package that updates the drivers and the Certificate. It worked for my HP Deskjet 6980 with Mojave 10.14.6 so I can once again print. Here's a link to the solution discussion on the HP community forum. Look for the Accepted Solution entry in the discussion.

https://h30434.www3.hp.com/t5/Printing-Errors-or-Lights-Stuck-Print-Jobs/Driver-Certificate-Expired-Yesterday/m-p/7826768#M895582

I tried this file you suggested, (after previously downloading several different HP driver sets) but the file continually fails to download completely--error message that this file is corrupted. I tried Firefox and it failed to download as well. Any suggestions?

I first tried downloading the file using the Chrome browser and it kept failing. I was able to get the ftp file transfer to work in Safari. When I selected the link a little message appeared in the upper right corner of the browser window asking me to confirm I wanted to download the file by ftp. After that it downloaded without any problems.

Thanks. I tried the ftp method and it went much more quickly--until the very end--and then it failed.

However, I just saw a post online that the printer issue was fixed between HP and Apple--someone at Apple figured it out.

I tried printing, and now it works.

Thanks for all your posts.

Is this the driver you are using: HPPrinterDrivers5.1.dmg?

I am using this driver, yes.

Maybe the problem is related to this certificate? The problem has appeared practically overnight for everybody on the same date.

So does that mean that we can't do anything until Apple (if they choose) comes up with the fix?

Not when Apple promotes its built-in software for printers.