in datapower response rule not getting data from backend even backend is working properly

Question

getting result while debugging in response rule

   <env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/">
   <env:Body>
      <env:Fault>
         <faultcode>env:Client</faultcode>
         <faultstring>Internal Error</faultstring>
      </env:Fault>
   </env:Body>
</env:Envelope

I configure one response rule including match action, transformation action and result action after hitting request to backend, backend showing valid response in debugger but response rule not picking up this backend response..

whats a solution for this one ?