The main connection was closed: the server committed a protocol violation. FTP

I have uploaded my file using the code below, it works great but for a while it throws this error. "The main connection was closed: the server committed a protocol violation" and stopped the process when I started it again, downloading the file using from any problem.

One thing I noticed, if I run this process to download multiple files, then I get this error someday, if I do less than 5 files, then it works great, any idea where and what I should look at.

I have searched google but found nothing for this solid solution, not even one of the msdn blog that says about a bug in FTPwebrequest but not sure.

Environment: C # 4.0, IIS FTP server.

Thanks in Advance

                FileInfo fileInf = new FileInfo(filename);
                FtpWebRequest reqFTP;

                // Create FtpWebRequest object from the Uri provided
                reqFTP = (FtpWebRequest)FtpWebRequest.Create
                         (new Uri(path + fileInf.Name));


                // Provide the WebPermission Credintials
                 reqFTP.Credentials = new NetworkCredential(user, pwd);

                // By default KeepAlive is true, where the control connection
                // is not closed after a command is executed.
                reqFTP.KeepAlive = false;


                // Specify the command to be executed.
                reqFTP.Method = WebRequestMethods.Ftp.UploadFile;

                // Specify the data transfer type.
                reqFTP.UseBinary = true;
                reqFTP.Timeout = -1;
                reqFTP.UsePassive = true;


                // Notify the server about the size of the uploaded file
                reqFTP.ContentLength = fileInf.Length;

                // The buffer size is set to 2kb
                int buffLength = 4096;
                byte[] buff = new byte[buffLength];
                int contentLen;

                // Opens a file stream (System.IO.FileStream) to read the file
                // to be uploaded
                FileStream fs = fileInf.OpenRead();


                try
                {
                    // Stream to which the file to be upload is written
                    Stream strm = reqFTP.GetRequestStream();

                    // Read from the file stream 2kb at a time
                    contentLen = fs.Read(buff, 0, buffLength);

                    // Till Stream content ends
                    while (contentLen != 0)
                    {
                        // Write Content from the file stream to the FTP Upload
                        // Stream
                        strm.Write(buff, 0, contentLen);
                        contentLen = fs.Read(buff, 0, buffLength);
                    }

                    // Close the file stream and the Request Stream
                    strm.Close();
                    fs.Close();
                }

      

        
        
        
      

    

Answer

reqFTP.KeepAlive = false; to "True" to get rid of the error in my case.