title: C# DotNetOpenAuth Oauth2 Client.AuthorizeRequest causes 404
body: <p>I am trying to authenticate requests to an api for a website using DotNetOpenAuth in C#.
  My code is as follows:</p>
  
  <pre><code>var serverDescription = new AuthorizationServerDescription();
  serverDescription.AuthorizationEndpoint = new Uri("https://--website--/authorize");
  serverDescription.TokenEndpoint = new Uri("https://--website--/token");
  serverDescription.ProtocolVersion = ProtocolVersion.V20;
  var client = new WebServerClient(serverDescription);
  client.ClientIdentifier = "--App Key--";
  client.ClientCredentialApplicator = 
      ClientCredentialApplicator.PostParameter("--App Secret--");
  var token = client.GetClientAccessToken();
  
  var request = (HttpWebRequest)WebRequest.Create("https://--website--/api/v1/me");
  request.Method = "GET";
  client.AuthorizeRequest(request, token);
  var response = request.GetResponse();
  var postreqreader = new StreamReader(response.GetResponseStream());
  var json = postreqreader.ReadToEnd();
  </code></pre>
  
  <p>The code gets the access token fine, it then creates a web request for the authenticated api method.
  Upon the request.GetResponse() line, I get a 404 error.<br>
  I am sure that this web address exists, I can visit it in my browser but I get a 500.<br>
  Aditionally, if I remove the line: client.AuthorizeRequest(request, token); then the response given is a 500 error. So clearly the address exists, but it looks like something to do with adding the authorization headers causes it to give a 404.</p>