title: from origin 'null' has been blocked by CORS policy: Cross origin requests
body: <p>This error occurred while calling up JSON.
  I don't know why this error is happening.</p>
  
  <pre><code>$.getJSON(url, function(data){
      console.log(data);
  });
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>Access to XMLHttpRequest at (this is JSON URL) from origin 'null' has been blocked by CORS policy: Cross origin requests are only supported for protocol schemes: http, data, chrome, chrome-extension, https.
  </code></pre>