Ftp使用SSL获取错误

Question

有以下代码：

            Console.WriteLine("Sending debt collection file via ftp.");
            var filename = Path.GetFileName(filetosend);
            // Get the object used to communicate with the server.
            var request = (FtpWebRequest)WebRequest.Create(FtpUrl + filename);
            request.Method = WebRequestMethods.Ftp.UploadFile;

            var secureString = new SecureString();
            foreach (var b in Encoding.Default.GetBytes(FtpPassword))
                secureString.AppendChar((char)b);
            request.Credentials = new NetworkCredential(FtpUsername, secureString);
            //request.Credentials = new NetworkCredential("", "");
            request.EnableSsl = true;

            ServicePointManager.ServerCertificateValidationCallback += ValidateRemoteCertificate;

            var sourceStream = new StreamReader(filetosend);
            byte[] fileContents = Encoding.UTF8.GetBytes(sourceStream.ReadToEnd());

            sourceStream.Close();
            request.ContentLength = fileContents.Length;

            var requestStream = request.GetRequestStream();
            requestStream.Write(fileContents, 0, fileContents.Length);
            requestStream.Close();

            var response = (FtpWebResponse) request.GetResponse();

            Console.WriteLine("Upload File Complete, status {0}", response.StatusDescription);
            //Console.ReadKey();

            response.Close();

我收到了这条消息：

System error.

Please contact Suburban software for assistance.
System error.
   at System.Net.FtpWebRequest.GetRequestStream()
   at SSS.DebtCollections.FtpToTransworld.Send(String filetosend) in C:\work\ArmEmail\ArmEmail\FtpToTransworld.cs:line 59
   at SSS.DebtCollections.Program.Main(String[] args) in C:\work\ArmEmail\ArmEmail\Program.cs:line 44
System error.
   at System.Net.PooledStream.PrePush(Object expectedOwner)
   at System.Net.ConnectionPool.PutConnection(PooledStream pooledStream, Object owningObject, Int32 creationTimeout, Boolean canReuse)
   at System.Net.FtpWebRequest.FinishRequestStage(RequestStage stage)
   at System.Net.FtpWebRequest.SyncRequestCallback(Object obj)
   at System.Net.FtpWebRequest.RequestCallback(Object obj)
   at System.Net.CommandStream.Dispose(Boolean disposing)
   at System.IO.Stream.Close()
   at System.IO.Stream.Dispose()

我可以使用这个程序从我的开发计算机发送，但工作站给我上面的消息。我不确定是什么。我已将程序添加到允许列表中，并且它在同一网络上运行。

任何建议