System failed to generate the PDF document. Please contact your system administrator

Greetings,

I am getting error while taking the PO print output in PDF.

I have done the setup for Document Type , Document Style, checked the "ICX: Numeric characters" and "XDO: Numeric characters"  is set.

Still getting the error :

"System failed to generate the PDF document. Please contact your system administrator

while trying to view the PDF output from *Inquire --> View Doc.

Please advise. Thank you !!