My old post had an error please consider this,
and add this code to reference.cs
protected override WebRequest GetWebRequest(Uri uri)
        {
            HttpWebRequest webRequest = (HttpWebRequest) base.GetWebRequest(uri);

            webRequest.KeepAlive = false;
            webRequest.ProtocolVersion=HttpVersion.Version10;
            return webRequest;
        }
This can solve the problem