C# Post Discord Webhook Error

Hey.
Im getting a Error (“Error: TrustFailure (A call to SSPI failed, see inner exception.)”) after Executing this code:

using (HttpClient httpClient = new HttpClient())
                {
                    System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

                    HttpResponseMessage httpResponseMessage = await httpClient.PostAsync(webhook, (HttpContent)httpContent);
                    
                }

Does anyone know why that happends?
Best regards.

Remove your SecurityProtocol tls12 and (in your constructor?) add

System.Net.ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;

This will validate all certicates, the server is not able to validate any