WebClient throws SocketException (Invalid argument)

Question

I use the code below in an attempt to create a file to an ftp server. However i get a socket exception. Can anyone help me solve this exception? Same issue seem to happen when I use the UploadFile(uri, filepath) function.

I tried with setting the credentials as NetworkCredentials too in the options of WebClient but getting the same result.

Got the same result on a remote ftp server too.

Im using .NET 4.7.1

byte[] xmlBytes = XmlDocumentToByteArray(xml);

WebClient webclient = new WebClient() {
    Proxy = null
};

Uri uri = new Uri("ftp://test:test@localhost/test.xml");
//Uri uri = new Uri("ftp://localhost/test.xml");
webclient.UploadData(uri, xmlBytes);

Exception: (In english: An invalid argument was supplied)

System.Net.WebException: Er is een ongeldig argument opgegeven ---> System.Net.Sockets.SocketException: Er is een ongeldig argument opgegeven
   bij System.Net.Sockets.Socket..ctor(AddressFamily addressFamily, SocketType socketType, ProtocolType protocolType)
   bij System.Net.ServicePoint.GetConnection(PooledStream PooledStream, Object owner, Boolean async, IPAddress& address, Socket& abortSocket, Socket& abortSocket6)
   bij System.Net.PooledStream.Activate(Object owningObject, Boolean async, GeneralAsyncDelegate asyncCallback)
   bij System.Net.PooledStream.Activate(Object owningObject, GeneralAsyncDelegate asyncCallback)
   bij System.Net.ConnectionPool.GetConnection(Object owningObject, GeneralAsyncDelegate asyncCallback, Int32 creationTimeout)
   bij System.Net.FtpWebRequest.QueueOrCreateConnection()
   bij System.Net.FtpWebRequest.SubmitRequest(Boolean async)
   --- Einde van intern uitzonderingsstackpad ---
   bij System.Net.WebClient.UploadDataInternal(Uri address, String method, Byte[] data, WebRequest& request)
   bij System.Net.WebClient.UploadData(Uri address, String method, Byte[] data)
   bij System.Net.WebClient.UploadData(Uri address, Byte[] data)
   bij ProbeOrderPlacement.Order.OrderSubmit.SubmitOrder(XmlDocument xml) in H:\VSWorkspace\VSTS\Quantore\Probe\ProbeOrderPlacement\Order\OrderPlacement.cs:regel 28

Also tried the following code, but it trows the same exception (but on .GetRequestStream())

FtpWebRequest request = (FtpWebRequest)WebRequest.Create(new Uri("ftp://127.0.0.1/test.xml"));
request.Method = WebRequestMethods.Ftp.UploadFile;
request.Proxy = null;
request.UseBinary = true;
request.Credentials = new NetworkCredential("test", "test");
request.ContentLength = xmlBytes.Length;

//Upload the data
using(Stream requestStream = request.GetRequestStream()) {
    requestStream.Write(xmlBytes, 0, xmlBytes.Length);
}

Exeption: (In english: An invalid argument was supplied)

System.Net.WebException: Er is een ongeldig argument opgegeven ---> System.Net.Sockets.SocketException: Er is een ongeldig argument opgegeven
   bij System.Net.Sockets.Socket..ctor(AddressFamily addressFamily, SocketType socketType, ProtocolType protocolType)
   bij System.Net.ServicePoint.GetConnection(PooledStream PooledStream, Object owner, Boolean async, IPAddress& address, Socket& abortSocket, Socket& abortSocket6)
   bij System.Net.PooledStream.Activate(Object owningObject, Boolean async, GeneralAsyncDelegate asyncCallback)
   bij System.Net.PooledStream.Activate(Object owningObject, GeneralAsyncDelegate asyncCallback)
   bij System.Net.ConnectionPool.GetConnection(Object owningObject, GeneralAsyncDelegate asyncCallback, Int32 creationTimeout)
   bij System.Net.FtpWebRequest.QueueOrCreateConnection()
   bij System.Net.FtpWebRequest.SubmitRequest(Boolean async)
   --- Einde van intern uitzonderingsstackpad ---
   bij System.Net.FtpWebRequest.GetRequestStream()
   bij ProbeOrderPlacement.Order.OrderSubmit.SubmitOrder(XmlDocument xml)

Answer 1

Based on this comment by Hans Passant

This is a very low-level mishap, nothing to do with the arguments you passed since they don't get used until later. The underlying OS function (WSASocket) failed, seemingly unhappy about creating a TCP socket. That should never happen of course. But crap happens with networking code, there is always far too much junk hanging off a socket that professes to keep your machine safe and running smoothly. Disable the installed anti-malware product first, any kind of firewall and whatnot next.

I figured out that for my case the problem was the fact that I had the repository of my solution on a Network drive my company provides me. My best guess is that the upload failed due to underlying security measures although I didn't dig into it deep enough to be able to prove this was the case.

Creating a new local repository on my c drive overcame the issue.

So advice for feature readers that experience the same thing, would be to look at the underlying infrastructure to overcome the problem.