SOAPException

Dear Experts,
I got the following error message after a web service connector was executed:
SOAPException:[ISS.0088.9136] A WattEvaluationException was thrown by the XQL Query engine

Please show me how to solve it. Thank you.

To quote the robot, Johnny-5 “Need more input, Stephanie.” What service is throwing the exception? What is the Flow statement on which this is occuring? What is the XQL query?