Hi I am Also facing Same issue however i am Getting 200 ok
Even then i have error
Definitions object is present in the response | JSONError: Unexpected token β<β at 1:1 <definitions targetNamespace="urn:microsoft-dynamics-schemas/codeunit/POSTransa ^
and my test script which is Auto Generated by Postman
pm.test("Response status code is 200", function () {
pm.response.to.have.status(200);
});
pm.test("Content-Type header is text/xml", function () {
pm.expect(pm.response.headers.get("Content-Type")).to.include("text/xml");
});
pm.test("Definitions object is present in the response", function () {
const responseData = pm.response.json();
pm.expect(responseData.definitions).to.exist;
});
Hey @shahrukhgaffar01 
Welcome to the Postman community 
As it is an XML response you would need to parse that with pm.response.text()
and then assertion reference you have would need to be changed to match the XML response.
pm.test("Definitions object is present in the response", function () {
const responseData = pm.response.json();
pm.expect(responseData.definitions).to.exist;
});
Youβre trying to parse that response as JSON so itβs throwing a JSONerror.
Hey World, How r u ?
I have tried below code and error went away
var responseText = pm.response.text()
responseText = responseText.replace('<?xml version=\'1.0\'?>','')
var jsonData = xml2Json(responseText);
var uid = jsonData.methodResponse.params.param.value.int
pm.collectionVariables.set("uid", access_token);