Unable to select wildcard SSL certificate for subdomain in Plesk: SSL certificate is not available for selection

Symptoms

After installing a Let's Encrypt wildcard SSL certificate on a main domain, this SSL certificate is not available for subdomain selection at Domains > test.example.com > Hosting Settings page.

Cause

Inconsistency in the Plesk database: main domain and its subdomain have different certificate repositories.

Resolution

1. Connect to the Plesk server via SSH.

2. Create backup of the Plesk database:

   # plesk db dump psa > /root/psa_dump.sql

3. Find cert_rep_id of the domain in question, replacing example.com with an actual domain name:

   # plesk db "SELECT cert_rep_id FROM domains WHERE name='example.com'"
   +-------------+
   | cert_rep_id |
   +-------------+
   | 2 |
   +-------------+

4. Set the same cert_rep_id for the subdomain of this domain, replacing test.example.com with an actual subdomain name:

   # plesk db "UPDATE domains SET cert_rep_id=2 WHERE name='test.example.com'"