Sending XML data through a http request

Hi all,

I'm having trouble sending XML data through a html POST request.

The errors are:

LogMgrWrtr [O.N.H.L.A.ABLSocketLibrary ERROR] EXTRACT ENTITY ERROR
LogMgrWrtr Error(s) raised:
LogMgrWrtr X-NODEREF or X-DOCUMENT LOAD got an error: FATAL ERROR: file 'MEMPTR', line '1', column '1', message 'invalid document structure'. (9082) (9082)
LogMgrWrtr [O.N.H.L.A.ABLSocketLibrary ERROR] EXTRACT ENTITY: Response entity contains raw message body
LogMgrWrtr [O.N.H.L.A.ABLSocketLibrary ERROR] EXTRACT ENTITY: Response Content-Type changed from application/xml to application/octet-stream
An Progress.Lang.SysError has occurred:
Invalid cast from OpenEdge.Core.Memptr to OpenEdge.Core.WidgetHandle. (12869)

This is the code I am using to make the request:

DEFINE VARIABLE lcXmlResponseData AS LONGCHAR NO-UNDO.
DEFINE VARIABLE hXmlRequestData AS HANDLE NO-UNDO.
DEFINE VARIABLE hXmlResponseData AS HANDLE NO-UNDO.
DEFINE VARIABLE oXmlRequestData AS WidgetHandle NO-UNDO.
DEFINE VARIABLE oXmlResponseData AS WidgetHandle NO-UNDO.
DEFINE VARIABLE oHttpRequest AS IHttpRequest NO-UNDO.
DEFINE VARIABLE oHttpResponse AS IHttpResponse NO-UNDO.

CREATE X-DOCUMENT hXmlRequestData.
hXmlRequestData:LOAD("LONGCHAR", <xml_data_in_longchar>, FALSE).
oXmlRequestData = NEW WidgetHandle(hXmlRequestData).
oHttpRequest = RequestBuilder:Post(SessionManager:ExchangeServerURI, oXmlRequestData):ContentType("application/xml"):AcceptXml():Request.
oHttpResponse = ClientBuilder:Build():Client:Execute(oHttpRequest).
oXmlResponseData = CAST(oHttpResponse:Entity, WidgetHandle).
hXmlResponseData = oXmlResponseData:Value.
hXmlResponseData:SAVE("LONGCHAR", lcXmlResponseData).

The XML data is:

<?xml version="1.0"?>
<BulkLoad>
   <CustomerId>...</CustomerId>
   <DataType>...</DataType>
   <StartRangeTime>...</StartRangeTime>
   <EndRangeTime>...</EndRangeTime>
   <ImpersonationInfo>...</ImpersonationInfo>
</BulkLoad>

If I change the X-DOCUMENT:LOAD validation parameter to TRUE, I get the following error:

An Progress.Lang.SysError has occurred:
X-NODEREF or X-DOCUMENT LOAD got an error: 'no declaration found for element 'BulkLoad''. (9082)

There is this KB article about the error, but there is no external XSD for which the validation should fail:
https://knowledgebase.progress.com/articles/Article/XML-validation-against-external-XSD-fails-starting-with-OpenEdge-11-6

Best regards,
Andrew