How? Finding PDF errors?

Acrobat 9 Reader opens and displays the document correctly, and
without warnings or errors. But when printing the doucment it does
indeed print it correctly, but after shows an error dialog: An error
exists on this page. Acrobat may not display the page correctly.
Please contact the person who created the PDF document to correct the

Acrobat Pro 9 Preflight report PDF syntax issues reveals
Invalid content stream state for operator (1 match on 1 page)

We have used PDFNet in several projects now with tremendous success,
but this has us stumped. How can I better isolate the problem so that
we can fix it?

Thanks for any hints tips or tricks.

Based on your description it seems that the PDF file may be coorupt
(and perhaps there is a bug in Acrobat). You may want to try to use
PDF/A Manager ( or PDFACompliacne
class in PDFNet (see PDFATest sample project) to fix this broken file.
In some cases, PDFNet and PDF/A Manager could fix corrupt PDF files
(although this is not always guaranteed). Also, processing file using
PDFNet may give you a better error description than the one you get
using Acrobat.

You could also use CosEdit ( to inspect
the PDF file and to narrow down on the possible source of the error.