public async void setTableDevelopers() { try { List <Developer> developers = await DefaultController.GetDevelopers(); DataTable tableDevelopers = Utils.Util.ConvertToDataTable <Developer>(developers); GridView2.DataSource = tableDevelopers; GridView2.DataBind(); } catch (Exception ex) { string script = @"<script type='text/javascript'> alert('{0}'); </script>"; script = string.Format(script, ex.Message); ScriptManager.RegisterStartupScript(this, typeof(Page), "alerta", script, false); } }