Outdated dB driver - The libmysqlclient driver version is less than the minimum required version.

Encountered this problem:
Database Version
10.5.22-MariaDB-cll-lve
The libmysqlclient driver version 3.1.22 is less than the minimum required version. Upgrade to libmysqlclient version 5.5.3 or up, or alternatively switch mysql drivers to MySQLnd version 5.0.9 or up.
System MariaDB

The solution to that problem is pretty simple:

1. Login to your cPanel or similar
2. Select the "Select PHP Version" icon or similar
3. Deselect both the "mysqli" and "mysqlnd" options
4. Select "nd_pdo_mysql"; then "mysqlnd" will be turned back on automatically
   
   https://www.drupal4u.org/tips-and-tricks/10338-mariadb-log-cll-lve-libmysqlclient-driver-version-3120-less-minimum-required