This is about a fresh Puppy installation of xenialpup. I don't know if this is a Puppy problem or an Ubuntu Xenial problem. Also, I'm guessing that it might not be necessarily a printer problem.
In any case, when I installed HPLIP, and added an HP printer with Cups, I kept getting the "filter failed" message when I tried to print a test page from Cups. I installed the hp-toolbox GUI, thinking it might pull in some missing dependencies. When I tried to run that, it complained about /usr/bin/python3 being missing or not working, I forget which. I found that the /usr/bin/python3 symlink pointed to python3.6, which wasn't there, though python3.5 was. I deleted the python3 symlink and re-created it to point at python3.5. After I did that, I was able to print the test page to my HP printer.