- Plesk Onyx for Windows
SSL certificates were manually exported as .pfx files and bound via IIS interface.
SSL certificates randomly becoming unbound from websites in IIS on Plesk server.
Websites were migrated to a new Plesk server.
Certificates were not bound to domains in Plesk UI. For normal work SSL certificates should be imported to Plesk and bound with websites using Plesk user interface, not via IIS interface.
2. Install certificates for all domains via Plesk UI according to this guide (section Purchased or custom SSL certificate).