title: The underlying connection was closed. The server committed a protocol violation
body: <p>I am trying to get the directory list of a FTPS FileZilla server using the code below :</p>
  
  <pre><code>ftpRequest = (FtpWebRequest)FtpWebRequest.Create(host + "/" + directory);
  ftpRequest.EnableSsl = true;
  
  ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(ValidateCertificate);
  ftpRequest.Credentials = new NetworkCredential(user, pass);
  ftpRequest.UseBinary = true;
  ftpRequest.UsePassive = true;
  ftpRequest.KeepAlive = true;
  ftpRequest.Method = WebRequestMethods.Ftp.ListDirectory;
  ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();
  </code></pre>
  
  <p>I got an exception when <code>FtpWebResponse)ftpRequest.GetResponse()</code> is executed :</p>
  
  <blockquote>
    <p>the underlying connection was closed. The server committed a protocol
    violation.</p>
  </blockquote>
  
  <p>When I switch to normal FTP connection. Everything works correctly.</p>
  
  <p>Did I miss something to establish this FTPS connection ?
  thanks for help</p>