When you convert PDF files to PDF/a documents with the DocConverterService in LiveCycle ES2, you receive the following error:
<ViolationDetail key="PDFA_METADATA_020_MISMATCHED_TYPE_FOR_PROPERTY"> <MetadataProperty namespaceURI="http://purl.org/dc/elements/1.1/" name="date"/>
This issue is fixed in LiveCycle ES3 and later versions. There is a patch available for LiveCycle ES2 SP1 and SP2, so contact enterprise support if you require this patch.
Using LiveCycle Designer ES, you can enter values for the XMP metadata in the PDF file, without any validation on the values entered. In this case, the date was entered in the following format:
Looking at the schema for the XMP element http://purl.org/dc/elements/1.1/ it suggests the date be formatted according to ISO 8601, which defines dates in the format:
This formatting was the cause of the issue. If the date was entered in ISO 8601 format, then the error does not occur.