Help with SOAP Web Service: Invalid XML format. Unable to save...

I am receiving this error message when executing my SOAP Web Service call in v11.

My settings are as follows. Step 1 has correct URI as validated in SOAP UI. Step 3 is valid

WSDL works in SOAP UI

There is a possibility that the response contains a character not supported by XML, please check this document for more details

This error indicates some issue within the XML file. Please check it for validity and format errors and retry.