title: Error can't redefine non-configurable property "userAgent"
body: <p>Lately we have been getting a lot of javascript errors &quot;can't redefine non-configurable property &quot;userAgent&quot;&quot;.</p>
  <p>We don't attempt to redefine userAgent in our code. We barely even reference userAgent. The only places would be in code like the following:</p>
  <pre><code>var browser_msie = (navigator.userAgent.match(/msie/i) || navigator.userAgent.match(/trident/i)) ? true : false;
  </code></pre>
  <p>I am wondering if this error is rather coming from some bad browser behavior. It only started showing up recently.</p>
  <p>Last evening we got over 20,000 of such error messages, and all from the same member of our service.</p>
  <p>EDIT</p>
  <p>The error information is as follows:</p>
  <p>Error Message:</p>
  <pre><code>Message: TypeError: can&amp;amp;#39;t redefine non-configurable property &amp;amp;#34;userAgent&amp;amp;#34;
  URL: https://www.rephunter.net/member-home.php
  Line:1
  Column:130
  Stack:@https://www.rephunter.net/member-home.php:1:130
  
  
  Error Traceback: 
  
  #0 Called backtrace in file /var/www/rephunter/www/webroot/include/error-handler-inc.php as line #68
  #1 Called error_handler in file  as line #
  #2 Called trigger_error in file /var/www/rephunter/www/webroot/ajax/javascript-error.php as line #14
  </code></pre>
  <p>Unfortunately this offers no help, as line 1 of the page is just <code>&lt;!DOCTYPE html&gt;</code>. I don't see how to get to that part of the code. Of course if that were possible it might be easy to see the cause of the issue.</p>
  <p>I recall in the past the Dev Tools might have given a &quot;spiders view&quot; of the page, but now I only see the DOM on the Elements tab, and Sources. Both of these are formatted and their is no way to see what &quot;line 1 char 130&quot; means.</p>