Explicit proxy with user notification pages (Notify) enabled.
User notification pages are displayed for HTTP sites.
When accessing HTTPS sites, the notification pages are not displayed, resulting in a blank page being shown in the web browser.
SSL interception is not configured.
In an explicit deployment, if user notification policy on the ProxySG or Advanced Secure Gateway (ASG) works for HTTP sites but not HTTPS sites, then the ProxySG or ASG needs to be configured to intercept SSL. If the ProxySG or ASG does not have SSL-Intercept configured, the ProxySG or ASG appliance cannot view the request and cannot send notification pages to the client. The ProxySG or ASG uses TCP-Tunnel to proxy HTTPS requests to servers. See Configure SSL intercept for an explicit deployment using a self-signed certificate for instructions to set up SSL intercept.