FtpWebRequest Error

Question

I'm running the following:

            try
        {
            var ftpWebRequest = (FtpWebRequest)WebRequest.Create("ftp://webftp.ftp.com");
            ftpWebRequest.Credentials = new NetworkCredential("user", "password");
            ftpWebRequest.Method = WebRequestMethods.Ftp.UploadFile;
            using (var inputStream = File.OpenRead(@data))
            using (var outputStream = ftpWebRequest.GetRequestStream())
            {
                var buffer = new byte[1024 * 1024];
                int totalReadBytesCount = 0;
                int readBytesCount;
                while ((readBytesCount = inputStream.Read(buffer, 0, buffer.Length)) > 0)
                {
                    outputStream.Write(buffer, 0, readBytesCount);
                    totalReadBytesCount += readBytesCount;
                    var progress = totalReadBytesCount * 100.0 / inputStream.Length;
                    uploader.ReportProgress((int)progress);
                }
            }
        }
        catch (Exception es)
        {
            MessageBox.Show(es.ToString());
        }

@data is the full local path to the file.

The error i receive everytime is as follows:

System.Net.WebException: The requested URI is invalid for this FTP command. at System.Net.FtpWebRequest.GetRequestStream()

I've tried the ftp connection via cmd and it works perfectly fine.