May 26, 2019#ASP.NET#TutorialHow to change security protocol to tls1.2 in IIS/ASP.NET?Edit Global.asax file. Import the System.Net class and then change the security protocol to tls1.2 in the Applicatin_Start method. <%@ Application Language="C#" %> <%@ Import Namespace="System.Net" %> <script runat="server"> void Application_Start(object sender, EventArgs e) { // Enforce the security protocol to TLS 1.2 ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12; } </script>