Problem Description
When attempting to apply a Let's Encrypt certificate to a subdomain, Plesk shows one or two warnings:
- Your domain is not secured with a valid SSL/TLS сertificate. Order or upload one to secure your domain.
- No CA plugins available.
Problem Resolution
This occurs when the parent domain has a wildcard SSL certificate installed. For example: You want to install a certificate on subdomain.mydomain.com and you have, in the past, generated a wildcard certificate for mydomain.com
The solution is to simply apply the wildcard certificate to subdomain.mydomain.com. Here's how:
- In Plesk go to Websites & Domains
- Select "Hosting Settings" under your subdomain (e.g.: subdomain.mydomain.com)
- Look for the "Certificate" dropdown and select your wildcard certificate from the list. It should be labeled like: "Let's Encrypt Certificate for mydomain.com".
- Press OK or Apply
After about 90 seconds the certificate should be applied successfully.
