Place the line which you are having an error in a try-catch block and see what is the exception you are getting while debugging it.
WebRequest request = WebRequest.Create("url");
try
{
using (WebResponse response = request.GetResponse())
{
Console.WriteLine("Won't get here");
}
}
catch (WebException e)
{
using (WebResponse response = e.Response)
{
HttpWebResponse httpResponse = (HttpWebResponse) response;
Console.WriteLine("Error code: {0}", httpResponse.StatusCode);
using (Stream data = response.GetResponseStream())
{
string text = new StreamReader(data).ReadToEnd();
Console.WriteLine(text);
}
}
}