Validation of ZUGFeRD PDF/A-3a brings up "Not a PDF/A-3" result

[svenlohberg]

I am using the PDF XPansion SDK to generate ZUGFeRD PDF documents. These are created as PDF/A-3a documents. A validation of these files always brings up the message "Not a PDF/A-3" and the files are marked as invalid.

Shouldn't all PDF/A-3 files be valid independent from the used flavor a, b or u (PDF/A-3a, PDF/A-3b, PDF/A-3u)?

Unfortunately the SDK does not seem to allow creating PDF/A-3 documents without any flavor.

[jstaerk]

Hello

I am using the PDF XPansion SDK to generate ZUGFeRD PDF documents. These are created as PDF/A-3a documents. A validation of these files always brings up the message "Not a PDF/A-3" and the files are marked as invalid.

Shouldn't all PDF/A-3 files be valid independent from the used flavor a, b or u (PDF/A-3a, PDF/A-3b, PDF/A-3u)?

They are. And AFAIK Mustang does not restrict to a, b or u. For the PDF validation mustang uses verapdf, have you checked e.g. with verapdf.org itself if the document is proper PDF/A?

kind regards
Jochen