You should add a try/catch to handle any errors.
FtpWebRequest req = (FtpWebRequest)WebRequest.Create(@"ftp://" + **strUploadIP** + @"/" + strUser);
req.Method = WebRequestMethods.Ftp.MakeDirectory;
req.Credentials = new NetworkCredential(strUusername, strUpassword);
try {
using (var resp = (FtpWebResponse)req.GetResponse()) {
Console.WriteLine(resp.StatusCode);
}
} catch {
// TODO: Handle exception
}