Could not parse message content to add interface element REST Adapter

Hi all,

I am doing a synchronous scenario from REST to ECC. I am using @ Vadim Klimov blog REST Adapter in PI/PO: Enhanced XML/JSON Conversion

to convert xml message to JSON flow in the response/

I am getting this error " Could not parse message content to add interface element".

These are the screen shots of my structure and CC. What possible could be the reason?

Harish Babu