I am trying to upload a thumbnail image to a part item (innovator.part.thumbnail)

The method for this is the setfileproperty method.

I have written a function to do this, but it failt to create a new file in the vault.  The other updates work fine and the part.thumbnail property does populate with some unknown GUID

Public Sub RegisterArasPart(strPartNumber As String _
 , strName As String _
 , strDescription As String _
 , strClassification As String _
 , strLegacyNumber As String _
 , strPDMDocumentID As String _
 , strImagePath As String)

 'Update an existing Aras Item and populate the thumbnail
 'Note: I ensured that the file specified is on the server (or available)

 Dim NewPartItem As Aras.IOM.Item = inn.newItem("part", "add")
 NewPartItem.setProperty("item_number", strPartNumber) 
 NewPartItem.setProperty("name", strName)
 NewPartItem.setProperty("description", strDescription)
 NewPartItem.setProperty("pdmdocumentid", strPDMDocumentID)
 NewPartItem.setProperty("classification", strClassification)
 NewPartItem.setProperty("_legacy_number", strLegacyNumber)
 NewPartItem.setFileProperty("thumbnail", strImagePath) 'This fails to upload the file given by the strImagePath.

 DisconnectFromAras() 'This is my function to disconnect

End Sub