Not able to access data produced by server API in Javascript but works on Postman

This is a strange problem and I tried to debug it through the day with no effect. I have written a REST API in Spring 4 and it seems to be working fine. I've tested the links with postman, they work fine and even when I test it on the browser it works fine. So my works like this, If a I make a call to,

http://localhost:9000/myapi/receivedMessags/myUserId

I get JSON of this form,

[{"senderId":"myUSerId","receiverId":"mySenderId","mediaId":"22797361348"},{"senderId":"myUSerId","receiverId":"mySenderId","mediaId":"22797361348"},{"senderId":"myUSerId","receiverId":"mySenderId","mediaId":"22797361348"},{"senderId":"myUSerId","receiverId":"mySenderId","mediaId":"22797361348"}]

Which is perfectly valid JSON data.

Now I try to consume this data using the fetch-API. This is my function,

export function fetchMessages(url) {
  return fetch(url, { method: "get",
                      headers: {
                        "Content-type": "text/plain"
                      },
                      credentials: 'include',
                      mode: 'no-cors'})
    .then((response) => {
      return response.json();//A
    })
    .then((data) => {
      //console.log("data: ", data);
      // let messages = [];
      // for (let i = 0; i < data.length; i++) {
      //   let message = new Message(data[i].senderId, data[i].receiverId, data[i].mediaId);
      //   messages.push(message);
      // }
      console.log(data);
      //return messages;
    })
    .catch((error)=> {
      console.log("Request failed: ", error);
    });
}

This method fails to access the data. I fails with the error,

Request failed:  SyntaxError: Unexpected end of input(…)

After a lot of debugging I figured out that there's nothing wrong with the syntax and it fails at line A where it tries to parse the response to json. If I change that line to response.text() the syntax error goes away and I get blank, which means there's no data. My question is why am I not able to access the data, when I know my server code is working fine.

If it helps, here's the server code,

@RequestMapping(value = "/receivedMessages/{userId}",
                    method = RequestMethod.GET,
                    produces = MediaType.APPLICATION_JSON_VALUE)
    @ResponseBody
    public ResponseEntity getReceivedMessages(@PathVariable("userId") String userId) {

        List<Message> receivedList = null;

        try {
            receivedList = controller.getReceivedMessages(userId);
        } catch (Exception e) {

        }

        return new ResponseEntity(receivedList, HttpStatus.OK);
    }

Infact, I've tried to POST on the API as well(which works fine in POSTMAN) but fails using my front-end client. Any help highly appreciated.