title: JavaScript fetch - Failed to execute 'json' on 'Response': body stream is locked
body: <p>When the request status is greater than 400(I have tried 400, 423, 429 states), fetch cannot read the returned json content. The following error is displayed in the browser console</p>
  
  <blockquote>
    <p>Uncaught (in promise) TypeError: Failed to execute 'json' on
    'Response': body stream is locked</p>
  </blockquote>
  
  <p>I showed the contents of the returned response object as follows:</p>
  
  <p><a href="https://i.stack.imgur.com/WKmyO.png" rel="noreferrer"><img src="https://i.stack.imgur.com/WKmyO.png" alt="enter image description here"></a></p>
  
  <p>But I can still use it a few months ago.</p>
  
  <p>My question is as follows:</p>
  
  <ul>
  <li>Is this just the behavior of the Chrome browser or the fetch standard changes?</li>
  <li>Is there any way to get the body content of these states?</li>
  </ul>
  
  <p>PS: My browser version is Google Chrome 70.0.3538.102（正式版本） （64 位）</p>