PHP script '/var/www/vhosts/hoteldamontanha.com/httpdocs/includes/start.php' is protected by SourceGuardian and requires a SourceGuardian loader 'ixed.8.3.lin' to be installed.

1) Download the required loader 'ixed.8.3.lin' from the SourceGuardian site: http://www.sourceguardian.com/loaders/download.php?php_v=8.3.30&php_ts=0&php_is=8&os_s=Linux&os_r=3.10.0-1160.119.1.el7.tuxcare.els15.x86_64&os_m=x86_64
2) Install the loader to /opt/plesk/php/8.3/lib64/php/modules
3) Edit /var/www/vhosts/system/hoteldamontanha.com/etc/php.ini and add 'extension=ixed.8.3.lin' directive