ERROR #5003: Not implemented

I have a business operation which I want to run an d I keep getting the above error have tried trace and logging every stage but can not figure out why the error comes from I am expecting this service to run everytime it is called hence the implementation  so could anyone help out  please

Operation 

Class XmlToJsonOperation Extends (Ens.BusinessOperation, )
{
Parameter ADAPTER = "EnsLib.File.OutboundAdapter";
Property Adapter As EnsLib.File.OutboundAdapter;
Parameter INVOCATION = "Queue";
Property CompiledStyleSheet As %XML.XSLT.CompiledStyleSheet;
/// Style sheet to convert Message to Json
Property XLTStyleSheet As %String(MAXLEN = "");
Parameter SETTINGS = "XLTStyleSheet:Basic";
Method XmlToJson(pRequest As EnsLib.EDI.XML.Document, Output pResponse As Ens.Response) As %Status
{
 set tSC=$$$OK
 
    set oInStream = ##class(%Library.GlobalCharacterStream).%New()
   
    set outputiing =##class(%Stream.FileCharacter).%New()
 
    set tSC  = pRequest.OutputToLibraryStream(oInStream)
   
    if ($$$ISOK(tSC))
    {
     $$$TRACE("we in the if")
     $$$LOGINFO("we in the if")
   do ..OnInit()
   $$$LOGINFO("we in OnIT")
   set outputiing= ..getJSON(oInStream)
   $$$LOGINFO("On The Stream")
  set fileName="json.txt"
  set tSC=..Adapter.PutStream(fileName,outputiing)
 }
 Quit $$$ERROR($$$NotImplemented)
}
XData MessageMap
{
<MapItems>
 <MapItem MessageType="EnsLib.EDI.XML.Document">
  <Method>XmlToJson</Method>
 </MapItem>
</MapItems>
}
/// This user callback method is called via initConfig() from %OnNew() or in the case of SOAP Services from OnPreSOAP()
Method OnInit() As %Status
{
 
 set tXSL=..XLTStyleSheet ;; file path from parameter
 Set tSC=##class(%XML.XSLT.CompiledStyleSheet).CreateFromFile(tXSL,.tCompiledStyleSheet)
    set ..CompiledStyleSheet=tCompiledStyleSheet
   
    $$$TRACE("compliled sheet name"_..CompiledStyleSheet)
    $$$LOGINFO("gone pass the trace compile")
 Quit $$$OK
}
Method getJSON(inStream As %Stream)
{
 set tSC=$$$OK
 set tSC=..CompiledStyleSheet
  if ($$$ISERR(tSC))
   {
  $$$LOGINFO("Error on the Complied sheet")
  $$$LOGINFO(tSC) 
 }
 set tSC=inStream
 
  if ($$$ISERR(tSC))
   {
  $$$LOGINFO("Error on the instream")
  $$$LOGINFO(tSC) 
 }
 Set tSC=##class(%XML.XSLT.Transformer).TransformStreamWithCompiledXSL(inStream,..CompiledStyleSheet,.tOutput)
 If ($$$ISERR(tSC))
 {
  $$$LOGINFO("Error on the getJson")
  $$$LOGINFO(tSC)
 }
 
 quit tOutput
}
}