Thank you, that resolved the issue!

A little more information.

This is the XML I have:

<?xml version="1.0" encoding="UTF-8"?>
<ICNARC xmlns="http://tempuri.org/ICMPDSv3_1.xsd">
   <ADMISSION>
      <InpatientSpellidentifier>53352</InpatientSpellidentifier>
      <ACON>U</ACON>
      <ACSD>0</ACSD>
   </ADMISSION>
</ICNARC>

This is the class

Class pacIPM.reqICNARC Extends (%Persistent, %Populate, %XML.Adaptor)
{ 
Property InpatientSpellidentifier As %String;

Property ACON As %String;

Property ACSD As %String;
}

However, I am getting the following error when I enable the service.

ERROR #6232: Datatype validation failed for tag, ADMISSION (ending at line 3 character 13), with value:

Is there anyway for me to see the actual stream or to confirm that the encoding is working/successful. I say this because I am sending the stream (PDF) to another system, but on the other system the PDF doesn't open, it errors...

I am not sure what has gone wrong.