Conform with the PDF/A-1a standard

[alisichkin]

Good afternoon!

We have long and successfully used your product - SynPDF to create PDF files from RTF.
PDF are created in PDF/A-1 format, with storing fonts inside the file
PdfDoc := TPdfDocumentGDI.Create(false, 0, true/APDFA1/);
PdfDoc.EmbeddedTTF := True;

Our users have noticed that the generated PDF files may not conform to the PDF/A-1a standard.
The https://www.pdf-online.com/osa/validate.aspx file uploaded to the site for verification displays the following message:
The key Type is required but missing.
The document does not conform to the requested standard.
The document doesn't provide appropriate logical structure information.
The document does not conform to the PDF/A-1a standard.

Is there any other parameter for SynPDF, changing which, I can achieve success when passing the PDF/A-1a compliance test?
What can I reply to my users?

With respect
Lisichkin Alexander.

I attach test pdf file:
TEST TEXT.pdf