This is either a firewall or ISP issue where your firewall or ISP has prevented you from accessing the administration server.
- Configure your firewall to make sure the Viewer, PDCViewer.exe, can access the Internet.
- If a firewall is not preventing PDCViewer.exe access: remove your Viewer keystore. Then copy and paste the registration link in the license email into your browser and change the HTTPS to HTTP in your browser’s address bar. Then press Enter.
- If that does not work, the license file may be getting corrupted when downloaded by the browser, so ask the Publisher of the document to send you a license file in a ZIP file that uses HTTP to connect to the licensing server instead of HTTPS. Remove your Viewer keystore before registering with your new license file.