Whenever we've seen a 'PCL XL' error, it was related to an issue with the printer driver. Though I've never seen it before with reports but only specifications (invoices, statements, etc).

If you are using an HP printer, take a look at the driver as it is probably set up with PCL emulation. One particular issue we know about is that the 'PCL 6' emulation isn't always good, and the same driver but 'PCL 5e' emulation works just fine - perhaps give that a try.

If you can preview the invoice posting journal report without that error, that is an indication that the problem lies with sending the print job to the printer - hardware/memory related and not likely to do with the program.

Did anything else change in addition to installing the upgrade (new computer, install Windows updates, etc)?