title: Web API 'Request' is null
body: <p>I'm trying to return an <code>HttpResponseException</code> from a POST Web API action using 'Request':</p>
  
  <pre><code>throw new HttpResponseException(Request.CreateErrorResponse(HttpStatusCode.NotFound, "File not in a correct size"));
  </code></pre>
  
  <p>When doing so, I get <code>Value cannot be null. Parameter name: request</code>.</p>
  
  <p>Essentially - <strong>Request</strong> is null.</p>
  
  <p>What am I missing?</p>
  
  <p>Thank you</p>