Database connection failed: User periodicos33 already has more than 'max_user_connections' active connections

Stack Trace:

File: /var/www/html/lib/pkp/includes/bootstrap.inc.php line 41
Function: PKPApplication->__construct()

File: /var/www/html/index.php line 65
Function: require("/var/www/html/lib/pkp/includes/bootstrap.inc.php")