title: Web API parameter is always null
body: <p>I have the following method in my Web API:</p>
  
  <pre><code>[AcceptVerbs("POST")]
  public bool MoveFile([FromBody] FileUserModel model)
  {
      if (model.domain == "abc")
      {
          return true;
      }
      return false;
  }
  </code></pre>
  
  <p>The <code>FileUserModel</code> is defined as:</p>
  
  <pre><code>public class FileUserModel
  {
      public string domain { get; set; }
      public string username { get; set; }
      public string password { get; set; }
      public string fileName { get; set; }
  }
  </code></pre>
  
  <p>I'm trying to call this through Fiddler but whenever I do the model is always set to null. In Fiddler I've sent the composer to use <code>POST</code>, the url is there and correct as the debugger in Visual Studio breaks when called. The Request I've setup as:</p>
  
  <pre><code>User-Agent: Fiddler 
  Host: localhost:46992 
  Content-Length: 127 
  Content-Type: application/json
  </code></pre>
  
  <p>The Request Body as:</p>
  
  <pre><code>"{
    "domain": "dcas"
    "username": "sample string 2",
    "password": "sample string 3",
    "fileName": "sample string 4"
  }"
  </code></pre>
  
  <p>But whenever I run the composer when the debugger hits the breakpoint it always shows model is null.    </p>