c# forbidden.html,c# - WebClient 403 Forbidden - Stack Overflow

403 may also be caused by TLS issues. To verify, you should check the text of the WebException.Response object.

catch (WebException ex)

{

if (ex.Response != null)

{

var response = ex.Response;

var dataStream = response.GetResponseStream();

var reader = new StreamReader(dataStream);

var details = reader.ReadToEnd();

}

}

If it is TLS then try adding this to your code to force TLS1.2.

For .net4:

ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;

For .net4.5 or later:

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;