title: Authorization Required - Error 401 only in firefox
body: <p>I made a website and put it on a local Linux server. I can access it without problem on Chrome and IE but firefox outputs this : </p>
  
  <blockquote>
    <p>Authorization Required</p>
    
    <p>This server could not verify that you are authorized to access the document requested. Either you supplied the wrong credentials (e.g., bad password), or your browser doesn't understand how to supply the credentials required.</p>
    
    <p>Additionally, a 401 Authorization Required error was encountered while trying to use an ErrorDocument to handle the request.</p>
  </blockquote>
  
  <p>I use "mod_auth_vas" on the server for single sign-on.</p>
  
  <p>I tried to delete the cache and cookies...<br>
  I tried to change the configuration and set <code>network.automatic-ntlm-auth.trusted-uris</code> with my website local address.<br>
  I also tried without proxy configured but none of this work.</p>
  
  <p>Any idea ?</p>
  
  <p>Regards !</p>