A postScript error unregistered points to an internal error of the RIP-software itself. It indicates the RIP encountered an undefined, undocumented statusdict operator. This is a rather obscure error.
- There is no easy way around this error. Contact the supplier of your RIP or printer.
- On a forum I found a procedure to fix issues with a PostScript error unregistered when printing to a HP 2605DN laser printer: right-click on your printer and select Properties > Printing Preferences > Advanced. Click on the Graphic line to expand it and select Download.