If you can’t print a PDF file to an HP LaserJet 4050 in Windows 7 or Windows 10, perhaps via a JetDirect network card (for a 4050N, but this probably doesn’t matter), here’s a possible solution to this frustrating problem:
This will cause the print driver to parse the incoming PDF file (which is made of PostScript internally), and then re-write new PostScript to send to the printer. This makes it work because Adobe has endlessly fiddled about with PostScript, especially for PDF files, and compatibility can sometimes suffer. Hope this helps someone!
LIFX Color 1000