title: Error in the console: Parameter is not of type Blob
body: <pre><code>&lt;script&gt;
          var file = document.getElementById("userFile").files[0];
          var reader = new FileReader();
          reader.readAsArrayBuffer(file);
          var byteArray = reader.result;
          console.log(byteArray);
  &lt;/script&gt;
  </code></pre>
  
  <p>This code produces this error in the console: Failed to execute 'readAsArrayBuffer' on 'FileReader': parameter 1 is not of type 'Blob'.</p>
  
  <p>To my understanding, a FileReader can accept both a Blob and File as a parameter because the File interface is based upon Blob.</p>