API Connect

I am trying to validate the request and response using parse followed by validate policy. 

Below is a simple policy to test this one. 

I am able to validate the request message properly. The setting to validate request message set to Validate against=body-param

I am able to capture the proper error message something like this:

Validate: temporary:///swagger/test-dev_ai-test-app_1.0.0.json:247: [JSV0002] Invalid object: the property 'xyzID' is missing.

But when I try to validate the response message with setting Validate against=response-param, 

I am not getting proper response back. The message I get is: 

Hi Sandeepkumar,
The response-param should get the validation schema from your path's response object. 

  /your-path:
    get:
      responses:
        '200':
          description: success
          schema:
            type: string  <=== or a $ref to a #/definitions (OAI2) or #/components (OAI3)
      consumes: []
      produces: []

Without seeing the API yaml file I can only speculate that the policy can't find the response schema.  Do you have access to the DataPower logs which would provide additional detail?
Regards,
Steve Linn