Respond.js (IE8, Bootstrap 3) runs on localhost but not in production

I've looked at all other IE8 / Respond questions. here but no luck so far.

When I test on localhost in IE8 emulator, I get the same error as in production, but Respond still works. First we see the broken page for a second, then the Bootstrap grid appears in place and everything is fine. However, in production, it remains broken.

The error I'm getting comes from the response-proxy.html file, line 46 (ajax): Permission denied

This is what I got in my base html file:

<!-- HTML5 Shim and Respond.js IE8 support of HTML5 elements and media queries -->
<!-- WARNING: Respond.js doesn't work if you view the page via file:// -->
<!--[if lt IE 9]>
    <script src="https://oss.maxcdn.com/html5shiv/3.7.2/html5shiv.min.js"></script>
    <script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>

{# <!-- Respond.js proxy on external server -->#}
<link href="https://maxcdn.bootstrapcdn.com/respond-proxy.html" id="respond-proxy" rel="respond-proxy" />

{# <!-- Respond.js redirect location on local server -->#}
    <link href="{% static "img/respond.proxy.gif" %}" id="respond-redirect" rel="respond-redirect" />

{# <!-- Respond.js proxy script on local server -->#}
    <script src="{% static "js/respond.proxy.js" %}"></script>

<![endif]-->

      

        
        
        
      

    

I tried to move it (end of head, end of body, etc.) but nothing works in production. We host our static files on S3 (CloudFront). We copied the CORS config from here: https://github.com/scottjehl/Respond/issues/152

I have also tried copying the react-proxy.html file to the file hosted with our static files, but I still get the same "Permit Denied" error.

Any solutions, workarounds, hints and suggestions are more than welcome.

Edit: I also tried some substitutions like css3-mediaqueries-js, but that didn't work at all.