How to Fix “The phpMyAdmin configuration storage is not completely configured, some extended features have been deactivated. To find out why click here.”

 This works with MariaDB. I assume it works with MySQL, but have not tried it.

Run this SQL in PHPMyAdmin with phpmyadmin selected:

GRANT SELECT, INSERT, UPDATE, DELETE ON phpmyadmin.* TO 'pma'@'localhost'; FLUSH PRIVILEGES;

Note that this does not grant "ALL PRIVILEGES" because it is not necessary.