PDF A-3b problem

[elcsoft]

I am generating a document using the commands below, but it isn't displaying as PDF/A-3 in Adobe. Can anyone help me with this? What am I doing wrong?
Programming language Visual foxpro with active-X VPE Version 7.4 Professional

poVPE.PDFALevel=VPE_PDF_A_LEVEL_3B
poVPE.AddColorProfile("GTS_PDFA1","sRGB_IEC61966-2-1","Custom","http://www.color.org","sRGB_IEC61966-2-1","sRGB_IEC61966-2-1")
poVPE.WriteDoc(tcPDFNAME)

[IDEAL Software Support]

Your code looks ok. When we create a PDF file here this way, Acrobat shows an annotation that the file is PDF/A.

Do you turn font embedding off after setting the property PDFALevel? According to the PDF/A specification, fonts must be embedded.

[IDEAL Software Support]

Do you output at least a single line of text? We did not try to create an empty PDF.

[elcsoft]

I found the error. The length of the "Author" field must not exceed 28 characters; otherwise, errors occur. Now I have another problem: a validator is returning the following message:

in German
XMP-Kennung pdfaid:part
Keine PDF/A-Kennung im XMP gefunden – die Datei beansprucht kein PDF/A.

URL of the validator is https://www.mediaatelier.com/de/Tools/PDFAChecker/

[elcsoft]

Your code looks ok. When we create a PDF file here this way, Acrobat shows an annotation that the file is PDF/A.

Do you turn font embedding off after setting the property PDFALevel? According to the PDF/A specification, fonts must be embedded.

Acrobat Reader says only
This file requires compliance with the PDF/A standard and has been opened in read-only mode.

[elcsoft]

Example Code with validation error

loVpe = createobject("VpeControl.VpeControl.74")
loVpe.OpenDoc()
loVpe.PDFALevel = 3
loVpe.EmbedAllFonts= .t.
loVpe.Author=alltrim(left("beispielfirma GmbH",28)) &&alltrim(puFIRMNAM)
loVpe.Creator="ABKS - http://www.elcsoft.de"
loVpe.title="test"
loVpe.Subject="test2"
loVpe.AddColorProfile("GTS_PDFA1","sRGB_IEC61966-2-1","Custom","http://www.color.org","sRGB_IEC61966-2-1","sRGB_IEC61966-2-1")
loVpe.print(1, 1,"ZUGFeRD-konforme Rechnung")
loVpe.WriteDoc("C:\testb\zugferd_rechnung.pdf")
loVpe.CloseDoc()
loVpe = .null.

[IDEAL Software Support]

We spent now an hour of working time for the whole case, writing test code, checking PDF specifications and verifying the metadata.

I ask you to purchase an hour of premium support in order to discuss this in further detail.

[IDEAL Software Support]

The PDF and PDF/A specifications do not restrict the length of the author field. Which software does report errors and what is exactly the error message?

Regarding the validation error: We checked now the metadata and we see no error. I guess the validator you are using is not good. We recommend veraPDF for PDF/A conformance checking, it does not report any problems.