title: Chrome HTTP OPTIONS (Preflight) Fails, but works in Postman
body: <p>I am building a SPA using AngularJS and .NET MVC/WebApi. I am having an issue with Chrome sending a pre-flight request for POST,PUT,DELETE operations (as it should), and getting a 404 response back from the server. The issue with this is that this request (with identical headers and HTTP method) is successful when using an API testing tool; Postman for this example.</p>
  
  <p>Here is the request/response information through Chrome:
  <a href="https://i.stack.imgur.com/ZyLom.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ZyLom.png" alt="enter image description here"></a></p>
  
  <p>IIS Trace: 2015-12-22 16:18:01 127.0.0.1 OPTIONS /api/v1/sidebar v=1450801081939 443 - 127.0.0.1 Mozilla/5.0+(Windows+NT+6.1;+WOW64)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/47.0.2526.106+Safari/537.36 <a href="https://etk.localtest.me/" rel="nofollow noreferrer">https://etk.localtest.me/</a> 404 0 0 6</p>
  
  <p>And here is the same request in Postman:</p>
  
  <p><a href="https://i.stack.imgur.com/z3PlN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/z3PlN.png" alt="enter image description here"></a></p>
  
  <p>IIS Trace: 2015-12-22 16:17:14 127.0.0.1 OPTIONS /api/v1/sidebar v=1449874981966 443 - 127.0.0.1 Mozilla/5.0+(Windows+NT+6.1;+WOW64)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/47.0.2526.106+Safari/537.36 - 200 0 0 7</p>
  
  <p>I would believe that my CORS configuration is configured correctly given it works in Postman?</p>
  
  <pre><code>&lt;httpProtocol&gt;
    &lt;customHeaders&gt;
      &lt;remove name="Access-Control-Allow-Origin" /&gt;
      &lt;add name="Access-Control-Allow-Origin" value="*" /&gt;
      &lt;remove name="Access-Control-Allow-Headers" /&gt;
      &lt;add name="Access-Control-Allow-Headers" value="Content-Type, Accept, Authorization" /&gt;
      &lt;remove name="Access-Control-Allow-Methods" /&gt;
      &lt;add name="Access-Control-Allow-Methods" value="GET, POST, PUT, DELETE, OPTIONS" /&gt;
    &lt;/customHeaders&gt;
  &lt;/httpProtocol&gt;
  </code></pre>
  
  <p>Has anyone else experienced this issue before? Any solutions/fixes?</p>