From what I can find, the Ricoh MP 2000 is c. 15 years old. PostScript support seems to be an option, rather than as standard.
invalidfont is certainly a PostScript error. It frequently occurs in Level 3 PostScript submitted to printers that only handle Level 2.
You could see if it will print a PDF from Adobe Reader or Acrobat using the "Print as Image" print option in those apps. This will RIP (rasterize) the page data on the computer instead of on the printer.
I don't know whether those Ricoh print drivers are capable of switching to PCL. You may need to check all the available options in the print dialog, and see if there's anything relating to fonts, or how the data is sent.