Hi Vineeth,
A HTTP Status Code 422 is not very common; what type of server do you call (i.e. is it custom-made or off the shelf)?
Sometimes it's used as validation feedback, i.e. it's the correct format (e.g. a String), but not an allowed value.
The 422 (Unprocessable Entity) status code means the server understands the content type of the request entity (hence a 415(Unsupported Media Type) status code is inappropriate), and the syntax of the request entity is correct (thus a 400 (Bad Request) status code is inappropriate) but was unable to process the contained instructions.
My approach would be to inspect the response body, as I would expect instructions from the server which field cannot be parsed. You could set the Log Level of REST Consume to Trace or add additional logging in the error handling of the Call REST activity. Could you share both your request and the response? This might give a hint where the error is.
Kind regards,
Johan