The following SSL error may occur when your client does not support TLS/SSL:
ERROR 2026 (HY000): SSL connection error: unknown error number
This error is most common on MySQL/MariaDB version 5.7.x, which is the default version in the Ubuntu repository. In this case, ensure you’re using the correct client version (8.x) to connect to your MySQL node.
For more information on installing the correct client version for your MySQL database, see How To Install the Latest MySQL on Ubuntu 18.04.