First check status of virtualizor

ps aux | grep virtualizor

If nothing is showing up in results

Check using command

systemctl status virtualizor

If still now working use command

service virtualizor restart

Stopping php-fpm: php-fpm is stopped
Stopping nginx: nginx is stopped
Stopping php-fpm: php-fpm is stopped
Stopping nginx: nginx is stopped
ERROR! MySQL server PID file could not be found!
/bin/systemctl
Starting php-fpm: Done…
Starting nginx: Done…
Starting MySQL.. SUCCESS!