- Plesk for Windows
- Plesk for Linux
- The website is marked as insecure in the web browser even when proper SSL certificate is installed in Plesk.
- Properties of the certificate in web browser indicate that certificate is issued by another certificate authority.
- When the site is loaded in web browser which runs on the server (locally), the website is marked as secure and a proper certificate is used.
Intermediate firewall (e.g. Sophos Firewall) substitutes SSL certificate by its own SSL certificate.
Disable this feature in firewall settings. For Sophos Firewall this action is described in external article Sophos Firewall: How to Bypass HTTPS Scanning for a Web Category.