Symptoms
-
Unable to add a server to Plesk 360 with one of the errors below:
The server has an invalid certificate
Hostname/IP does not match certificate's altnames
A self-signed certificate is installed
The certificate has expired
-
The hostname without a valid certificate or the IP address (i.e.
https://213.0.1.2:8443) is used to connect the server to Plesk 360
Cause
Plesk URL used to connect the server is not secured by a valid certificate.
Warning: The IP address can not be secured by a certificate in Plesk.
Resolution
-
Check if any related hostname is secured with an existing certificate under Tools & Settings > SSL/TLS certificates > Certificate for securing Plesk.
Note: That might be verified by using external resources as well - such as Qualsys SSL Labs, SSL Shopper.
If the certificate is presented and valid, use the related hostname:
- specify
https://server.hostname.com:8443on adding the server to Plesk 360 - access the Plesk UI via
https://server.hostname.com:8443and add the server to Plesk 360 from there
- specify
-
If there is no valid certificate, use the below article to secure Plesk URL:
How to secure a Plesk hostname on port 8443 with an SSL certificate (Let's Encrypt / other certificate authorities)