Using setMetaData from Doucment2.5

Hi,

I am trying change the metadata (Title, and Descriptions) of images given the GUID and version. I am trying to use the setMetaData method but I am not sure about what to put in the "psXMLRequiredCurrentMetadata" field. Currently, I am using  "Dim requiredXML As String = "<ishfields></ishfields>"" for that field. I do not have any required metadata that the program needs to check so I tried just leaving it empty. Is that the right approach? What should the "psXMLRequiredCurrentMetadata" field be if I do not have any required current metadata.

docClient.SetMetadata(GUID, lstVersions.Item(k), "en-US", "High", updatedXML, requiredXML)

That is how I currently use SetMetaData method. However, I get an error on this line. The exception I get is 'System.ServiceModel.Security.SecurityNegotiationException'  (SOAP negotiation failed). I am not sure if that is because of the psXMLRequiredCurrentMetadata field or not. What could be causing this issue if the account that I am using has admin access meaning I have write access.

Thanks