In MySQL Multiple instance, default instance is running, second instance is not
I looked and saw this

/usr/sbin/mysqld: Can't find file: './mysql/plugin.frm' (errno: 13)


That's a file permission issue.

Please go to Linux and run 

cd /var/lib/mysql-databases/
chown -R mysql:mysql mysqld2


Now, you should be able to restart mysql for port 3307