I have this error :

URL: /install/index.php?step=finish
ERROR:
Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/site.com/httpdocs/install/index.php on line 892
Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/site.com/httpdocs/install/index.php on line 893

URL: /admin/
ERROR:
Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/site.com/httpdocs/admin/controllers/admin.control.inc.php on line 34
Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/site.com/httpdocs/admin/controllers/admin.control.inc.php on line 35
Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/site.com/httpdocs/admin/controllers/admin.control.inc.php on line 52
Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/site.com/httpdocs/admin/controllers/admin.control.inc.php on line 53
Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/site.com/httpdocs/includes/classes/reefless.class.php on line 70

URL: site.com
ERROR:
Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/site.com/httpdocs/includes/control.inc.php on line 28
Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/site.com/httpdocs/includes/control.inc.php on line 29
Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/site.com/httpdocs/includes/control.inc.php on line 46
Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/site.com/httpdocs/includes/control.inc.php on line 47
Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/site.com/httpdocs/includes/classes/reefless.class.php on line 70