NetDocuments - Set Builder issue with NetDocuments

You can report it to NetDocs, but basically, this means that one of the PDFs used to build this set is damaged or corrupted.

A workaround is to use Adobe PDF - Combine Files in this guide > How to Create a PDF Portfolio in Adobe Acrobat (erinwrightwriting.com)

Or they will need to identify which one is the problematic PDF file, by excluding a file at a time and generating the set. So they take one pdf file off, they generate the set, if it fails, then take the next one and so. Once they find the one causing the issue, they can reprint that pdf back to pdf, using Microsoft to PDF printer, and try with the new version.

One way to find the file is that it usually happens with large files or ones with large images or issues with OCR.