UnknownDispositionMimeParts properties blank

[rivdiv]

Issue

I have an email messages with an attachment. The properties "FileName" and "ContentType" of the UnknownDispositionMimeParts are blank, even though the "OriginalMessage" property shows all those attachment details.

What would be the cause for this? Is there a fix?

Example

Details from the "OriginalMessage" property shows correct attachment details:

Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;
name="Daily Inventory Report - Automated.xlsx"
Content-Description: Daily Inventory Report - Automated.xlsx
Content-Disposition: attachment;
filename="Daily Inventory Report - Automated.xlsx"; size=118709;
creation-date="Thu, 14 Nov 2019 15:15:59 GMT";
modification-date="Thu, 14 Nov 2019 15:15:59 GMT"
Content-Transfer-Encoding: base64