The label "Path to the PHP-FPM init script" under System -> Additional PHP Versions -> PHP-FPM Settings is misleading, or basically wrong if you use it as labeled. Example: Path to the PHP-FPM init script: /usr/sbin/php-fpm7.4 The script /usr/local/ispconfig/server/mods-enabled/web_module.inc.php cuts away the path and uses the basename as servicename. The $initcommand adds ".service" and voilà executes systemctl reload php-fpm7.4.service Actual - at least in my case - the service is called php7.4-fpm.service Workaround: From an earlier statement in another post you CAN just enter e.g. "php-fpm7.4" without the path, but in fact you must and you must know that this is not the path but the actual service name. In my case this caused switching problems from php7.3 <--> php7.4 as you never get informed that the services don't reload/restart. Also be aware that if you do restart the services manually, you have to respect the order as the config files are moved to the other pool, so PHP will complain that another PHP is already using this port/file. Now this can also be solved by knowing what you do, naming the services the same etc.. but basically the label is wrong. "Path to the script" is wrong.