title: getting this error: "The remote server returned an error: (422) Unprocessable Entity." when doing post from C# to RoR
body: <p>This code is for an outlook plugin. We're trying to POST to a page and are getting this error:</p>
  
  <pre><code>The remote server returned an error: (422) Unprocessable Entity.
  </code></pre>
  
  <p>The C# code is here:</p>
  
  <pre><code>webClient.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
          ASCIIEncoding asciiEncoding = new System.Text.ASCIIEncoding();
          Byte[] postData = asciiEncoding.GetBytes("email=e2@email.com&amp;password=hunter2");
          char[] resultHTML = asciiEncoding.GetChars(webClient.UploadData("http://url", "POST", postData));
          string convertedResultHTML = new string(resultHTML);
  </code></pre>
  
  <p>Any idea what could be causing this?</p>