 <blockquote> <p>however I'm trying to deduce whether or not there is something interfering with the response in between the client an server.</p> </blockquote> <p>So you want to take a look what headers etc were sent even though the server is not sending the required <em>Access-Control-Allow-Origin</em> header along with the response?</p> <p>With <em>Google Chrome</em>, you can turn off some security features by launching it with the flag <code>--disable-web-security</code>, opening the browser up like this this will let you debug what you're asking about, but <strong>it won't prevent that error message for other people</strong>, you'd still need to fix it</p> <p>With <strong><em>your browser</em></strong> in this mode, you'll now be able to see the requests without the error being thrown, so be able to inspect them as normal</p> <hr> <p>An example of how you might open the browser like this from the <em>cmd</em> on a <em>Windows 7 (x64)</em> machine</p> <pre class="lang-sh prettyprint-override"><code>start "" "C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" "--disable-web-security" </code></pre> <p>For more, see <a href="http://stackoverflow.com/a/19317888/1615483"><strong>here</strong></a></p> <hr> <p><strong>Don't run <em>Chrome</em> like this for normal web browsing</strong></p>