Sep 13, 2018

How to solve: MySQL doesn't start. mysqld: Table 'mysql.plugin' doesn't exist

You need to use mysql_install_db to initialize the MySQL data directory and create the system tables that it contains, if they do not exist.
Such as:

mysql_install_db --user=mysql --datadir=/var/lib/mysql

You may want to
rm -rf  /var/lib/mysql/*
before you run it depends on your situation.