private void btnDownload_Click(object sender, EventArgs e) { Uri uri = new Uri("https://github.com/rogerclarkmelbourne/OpenGD77/releases"); wc = new WebClientAsync(40); ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12; this.progressBar.Value = 0; wc.DownloadProgressChanged += new DownloadProgressChangedEventHandler(downloadProgressChangedCallback); wc.DownloadStringCompleted += new DownloadStringCompletedEventHandler(downloadStringCompletedCallback); wc.DownloadFileCompleted += new AsyncCompletedEventHandler(downloadFileCompletedCallback); this.progressBar.Visible = true; enableUI(false); // Retrieve release webpage try { Application.DoEvents(); wc.DownloadStringAsync(uri); } catch (Exception ex) { MessageBox.Show("Error: " + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); enableUI(true); this.progressBar.Visible = false; return; } }