title: Response for preflight is invalid (redirect) error occur
body: <pre><code> test4 = () =&gt; {
  
          var xhr = new XMLHttpRequest();
          xhr.onreadystatechange = function () {
              if (xhr.readyState == 4 &amp;&amp; xhr.status == 200) {
                  var xmlDoc1 = xhr.responseText;
                  console.log("?", xmlDoc1)
  }
          xhr.open("GET",'http://www.naver.com');
   xhr.open("Access-Control-Allow-Origin",'http://www.naver.com');
          xhr.send();
          }
      }
  
  componentDidMount() {
  this.test4()
  }
  </code></pre>
  
  <p>error ==> XMLHttpRequest cannot load <a href="http://www.naver.com/" rel="nofollow noreferrer">http://www.naver.com/</a>. Response for preflight is invalid (redirect)
  please help me...</p>