title: In Firefox, getting error in console "XML Parsing Error: mismatched tag" for input
body: <p>I am getting the following error when opening up my page in Firefox (other browsers don't show this error). I am using HTML5 and if I try to put closing tags on the input, then the page fails validation.</p>
  
  <p><a href="https://i.stack.imgur.com/VLq6N.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/VLq6N.png" alt="enter image description here"></a></p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  
  &lt;html&gt;
    &lt;head&gt;
      &lt;meta http-equiv="Content-Type" content="text/html; charset=UTF-8"&gt;
      &lt;meta http-equiv="X-UA-Compatible" content="IE=Edge" &gt;
      &lt;!--... more here...--&gt;
    &lt;/head&gt;
    &lt;body&gt;
      &lt;!--... more here...--&gt;
      &lt;input type="text" id="wall_color_picker" onclick="startColorPicker(this)" title="Wall Color" value="#FFFFFF"&gt;
      &lt;!--... more here...--&gt;
    &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Edit 1: Firefox version is latest (59.0.2 (64-bit))</p>
  
  <p>Edit 2: Response headers:</p>
  
  <pre><code>Cache-Control   max-age=604800, public
  Connection  Keep-Alive
  Content-Type    text/html; charset=UTF-8
  Date    Tue, 24 Apr 2018 16:04:19 GMT
  Keep-Alive  timeout=5, max=100
  Server  Apache/2.4.6 (Red Hat Enterpri…penSSL/1.0.2k-fips PHP/5.6.35
  Strict-Transport-Security   max-age=31536000; includeSubdomains;
  Transfer-Encoding    chunked
  X-Powered-By    PHP/5.6.35
  </code></pre>