title: Possible network or Windows settings to cause HTTPS Ajax request to fail?
body: <p>I have built a product catalog site and it is running completely over HTTPS.</p>
  
  <p>Some people on my client's office are reporting that the Ajax loaded information on product popups is not visible.</p>
  
  <p>Product info is loaded like this:</p>
  
  <ol>
  <li><p>Customer goes to <a href="https://domain.com/" rel="nofollow">https://domain.com/</a> to view a category.</p></li>
  <li><p>He clicks one of the displayed items:</p>
  
  <pre><code>$(document).on("click", ".product-popup", function () {
     $('#modal-product-details .modal-body').load(
        "https://domain.com/modal-product-details.php?product_id=" + $(this).data('id'), function(){
        $('#modal-product-details .modal-loading').css("display", "none");
     });
  });
  </code></pre></li>
  <li><p>A Bootstrap modal opens and after a while the loading animation is hidden.</p></li>
  <li><p>For the problem users: nothing is shown in the modal. When the request is inspected in the network tab of Chrome tools, a yellow lock icon is shown and on the request headers there is a text "provisional headers only".</p></li>
  </ol>
  
  <p>But for most of the people the site is working completely ok! I can't repeat this behaviour with any configuration and still multiple people (but not all) on the same office are experiencing this.</p>
  
  <p><strong>What could cause the Ajax request to fail?</strong></p>
  
  <p>I have inspected following possible reasons:</p>
  
  <ul>
  <li>Not a HTTP request, but HTTPS.</li>
  <li>No insecure content in the loaded HTML (linked images etc.).</li>
  <li>Not a crossdomain request (same subdomain, same domain).</li>
  <li>No Javascript errors.</li>
  <li>No certificate warnings.</li>
  <li>The requested URL opens normally, when opened in a new tab.</li>
  </ul>
  
  <p>People who are experiencing this problem are experiencing it with all the browsers they have (Firefox, Chrome, IE). Could this be related to some settings the problem users have on their office LAN or some specific security settings on their Windows computers?</p>
  
  <p>Is there more reasons a jQuery load can fail?</p>