Q: Why is PDFNet throwing an exception when opening this PDF?
The document you sent contains a broken cross-reference table (i.e. it
is not a valid PDF). Acrobat attempts to fix the problem on the fly and
that is why the user is prompted to save the file in Acrobat Pro. If
you resave the file the error will go away. Alternatively you can
attempt to fix the xref table in PDFNet using XrefRebuilder class (or
Doc::FixBrokenDoc() in PDFNet 4.x or above).