Parsing of primary message content failed

All,

I'm new to SOAP, SOAPUI, and all things related to SOAP, so please bare with me.  I've created my first SOAP message using SOAPUI.  I'm 99% positive that I've tackled the WSSE security correctly (at least, I'm not getting authentication errors anymore), and all my elements are filled.  Correctly I think.  Now, the reply I'm getting from my remote end is an error that doesn't show up in Google.  Can anyone help with this please?

<SOAP:Envelope xmlns:SOAP="http://www.w3.org/2003/05/soap-envelope">
   <SOAP:Body>
      <SOAP:Fault>
         <SOAP:Code>
            <SOAP:Value>fault</SOAP:Value>
         </SOAP:Code>
         <SOAP:Reason>
            <SOAP:Text xml:lang="en"/>
         </SOAP:Reason>
         <SOAP:Detail>
            <wfe:invokeFault xmlns:wfe="http://www.caqh.org/SOAP/WSDL/CORERule2.2.0.wsdl">Sender-Parsing of primary message content failed</wfe:invokeFault>
         </SOAP:Detail>
      </SOAP:Fault>
   </SOAP:Body>
</SOAP:Envelope>

 I'm willing to pay for a valid message return at this point if anyone's interested because I'm so frustrated working with SOAP already.