How to return Non Json response - for a API Post Method

Question

How can we return a Non JSon Response, enter image description here

This is the response for one of My Post Method.

I am seeing an error Newtonsoft.Json.JsonSerializationException: Error converting value True to type.

This is where it is throwing exception

var jsonResponse = new Regex(@"Message : ({.*})").Match(ex.Reason.ToString()).Groups1.ToString(); abcd= JsonConvert.DeserializeObject(jsonResponse);