I added the namespace xmlns:mi

[yannicksaratoga]

As per MSN specification for the mRSS extension, it is required to have RSS elements such as: mi:hasSyndicationRights1</mi:hasSyndicationRights> mi:licenseId698525</mi:licenseId> mi:licensorNameLicensor name</mi:licensorName> mi:dateTimeWritten2016-01-10T10:00:00+0100</mi:dateTimeWritten>. So I extended the list of attributes of the namespace of this library to accept elements in form of "mi: "