SocketException in windows service

Aug 12, 2014 at 3:22 AM
Edited Aug 12, 2014 at 3:33 AM

I am trying to use FtpClient in windows service on Windows XP machine. No matter what I try, I am not even able to make the connection. Here is my code
            using(FtpClient con = new FtpClient()) {
                con.EnableThreadSafeDataConnections = false;
                con.Host = "XYZ";
                con.Credentials = new System.Net.NetworkCredential("anonymous","");
                using(var istream = con.OpenRead("/ROOT/Testing_Drop/Dump/chile.txt.txt", FtpDataType
                    string jobfilename = @"C:\Documents and Settings\manesing\My Documents\Work Area\Chile.txt";
                    using(var output=new BinaryWriter(File.Open(jobfilename, FileMode.Create))) {
                        byte[] buf = new byte[8192];
                        int read = 0;
                        try {
                            while ((read = istream.Read(buf, 0, buf.Length)) > 0) {
                        catch(Exception ex)
                            EventLog.WriteEntry("TestFTP","FTP: " +ex.Message);
                        finally {

The windows service always crash with below exception.
Service cannot be started. System.Net.Sockets.SocketException (0x80004005): An invalid argument was supplied
   at System.Net.Sockets.DynamicWinsockMethods.LoadDynamicFunctionPointer(SafeCloseSocket socketHandle, Guid& guid)
   at System.Net.Sockets.DynamicWinsockMethods.EnsureConnectEx(SafeCloseSocket socketHandle)
   at System.Net.Sockets.DynamicWinsockMethods.GetDelegate[T](SafeCloseSocket socketHandle)
   at System.Net.Sockets.Socket.ConnectEx(SafeCloseSocket socketHandle, IntPtr socketAddress, Int32 socketAddressSize, IntPtr buffer, Int32 dataLength, Int32& bytesSent, SafeHandle overlapped)
   at System.Net.Sockets.Socket.BeginConnectEx(EndPoint remoteEP, Boolean flowContext, AsyncCallback callback, Object state)
   at System.Net.Sockets.Socket.BeginConnect(EndPoint remoteEP, AsyncCallback callback, Object state)
   at System.Net.Sockets.Socket.BeginConnect(IPAddress address, Int32 port, AsyncCallback requestCallback, Object state)
   at System.Net.FtpClient.FtpSocketStream.Connect(String host, Int32 port, FtpIpVersion ...
As I could run the same code in the console application, I was suspecting the issue with user permission. However, when I tried .NET native FTPWebRequest class, it worked without any issues.
I can even connect to FTP server using sockets and it connects just fine. Windows service is running with admin user privileges.

Here is the FTPTrace output:
Disposing FtpClient object...
Disposing FtpClient object...
Disposing FtpSocketStream...
As you can see, even the connection is not made. Let me know if I am missing something in the code.
FtpClient version is 1.0.5281.14359
Aug 15, 2014 at 10:26 PM

For anyone facing the same issue, I finally found that the Winsock2 was corrupted on my system.

Followed the above link and was able to correct the problem. Now FtpClient works as it should.

Here is the workstation information
OS Name: Microsoft Windows XP Professional
OS Version: 5.1.2600 Service Pack 3 Build 2600
Marked as answer by mannbiher on 8/15/2014 at 2:26 PM