WSC Exception a a result of execution as a processing rule

Am using WebMethods IS 9.6 CoreFix 12 on Windows 8.1

Created a service to retrieve , map and send a file to a remote web service.

Produced a WSD using a client WSDL and Schema.
Used Pre 8.2 Compatibility and WM policy to ensure SOAP security header created as required.

When the service is run as an ordinary service the message is created and sent sucessfully, when integrated as a processing service during the invocation of the web service I receive the error

"[ISP.0085.9998E] Exception → com.wm.app.b2b.server.ServiceException: [ISS.0088.9431] Handler processing failed on the consumer: com.webmethods.ws.security.SecurityException: WS Security processing failed : Unable to convert SOAPMessage into a Document : {0}
"

Is it due to the fact that this when running with tighter coupling to TN that it is also trying to document the soap message being sent? If so is there a way to declare this in order to allow the consumption of this message.

Many thanks and kind regards,
Lawrence