Critical error

Can't connect to MySQL server
Line: 221

Stack trace:
#0 /var/www/vhosts/albergominerva.it/httpdocs/libs/Dinamo/DLog.class.php(111): DLog::logCritical('Can't connect t...', 0)
#1 /var/www/vhosts/albergominerva.it/httpdocs/libs/DB/DB.php(49): DLog::log('Can't connect t...', 4)
#2 /var/www/vhosts/albergominerva.it/httpdocs/global.inc.php(93): db->db()
#3 /var/www/vhosts/albergominerva.it/httpdocs/index.php(29): require_once('/var/www/vhosts...')
#4 {main}
Dinamo Cms RC2 V.1.3.2