This means you have not changed a setting before running server.sh, see steps from #16: This should work.
/usr/local/ispconfig/server/server.sh 07.09.2023-16:39 - DEBUG [plugins.inc:155] - Calling function 'check_phpini_changes' from plugin 'webserver_plugin' raised by action 'server_plugins_loaded'. 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: grep ^opcache.validate_root '/etc/php/7.3/apache2/php.ini' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: grep ^opcache.validate_root '/etc/php/7.3/fpm/php.ini' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: grep ^opcache.validate_root '/etc/php/7.3/cgi/php.ini' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: grep ^opcache.validate_root '/etc/php/5.6/cgi//php.ini' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: grep ^opcache.validate_root '/etc/php/5.6/fpm//php.ini' - return code: 0 07.09.2023-16:39 - DEBUG [server:177] - Found 2 changes, starting update process. 07.09.2023-16:39 - DEBUG [plugins.inc:118] - Calling function 'ssl' from plugin 'apache2_plugin' raised by event 'web_domain_update'. 07.09.2023-16:39 - DEBUG [plugins.inc:118] - Calling function 'update' from plugin 'apache2_plugin' raised by event 'web_domain_update'. 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: chattr -i '/var/www/clients/client2/web2' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: mount --bind '/var/log/ispconfig/httpd/celluledev.fr' '/var/www/clients/client2/web2/log' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: chattr +i '/var/www/clients/client2/web2' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: df -T '/var/www/clients/client2/web2'|awk 'END{print $2,$NF}' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: which 'setquota' 2> /dev/null - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: setquota -u 'web2' '0' '0' 0 0 -a &> /dev/null - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: setquota -T -u 'web2' 604800 604800 -a &> /dev/null - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: chattr -i '/var/www/clients/client2/web2' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: usermod --groups sshusers 'web2' 2>/dev/null - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: chattr +i '/var/www/clients/client2/web2' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: which 'apache2ctl' 2> /dev/null - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: which 'apache2ctl' 2> /dev/null - return code: 0 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:1891] - Writing the vhost file: /etc/apache2/sites-available/exemple.fr.vhost 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:1926] - Creating symlink: /etc/apache2/sites-enabled/100-exemple.fr.vhost->/etc/apache2/sites-available/exemple.fr.vhost 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: which 'apache2ctl' 2> /dev/null - return code: 0 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:3462] - Writing the PHP-FPM config file: /etc/php/7.3/fpm/pool.d/web2.conf 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:3483] - Removed PHP-FPM config file: /etc/php/7.4/fpm/pool.d/web2.conf 07.09.2023-16:39 - DEBUG [services.inc:56] - Calling function 'restartPHP_FPM' from module 'web_module'. 07.09.2023-16:39 - DEBUG [system.inc:2082] - Trying to use Systemd to restart service 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: systemctl is-enabled 'php7.4-fpm' 2>&1 - return code: 0 07.09.2023-16:39 - DEBUG [web module.inc:316] - Restarting php-fpm: systemctl reload php7.4-fpm.service 07.09.2023-16:39 - DEBUG [services.inc:56] - Calling function 'restartPHP_FPM' from module 'web_module'. 07.09.2023-16:39 - DEBUG [system.inc:2082] - Trying to use Systemd to restart service 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: systemctl is-enabled 'php7.3-fpm' 2>&1 - return code: 0 07.09.2023-16:39 - DEBUG [web module.inc:316] - Restarting php-fpm: systemctl reload php7.3-fpm.service 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:2009] - Apache status is: running 07.09.2023-16:39 - DEBUG [services.inc:56] - Calling function 'restartHttpd' from module 'web_module'. 07.09.2023-16:39 - DEBUG [system.inc:2082] - Trying to use Systemd to restart service 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: systemctl is-enabled 'apache2' 2>&1 - return code: 0 07.09.2023-16:39 - DEBUG [web module.inc:246] - Restarting httpd: systemctl restart apache2.service 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:2012] - Apache restart return value is: 0 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:2023] - Apache online status after restart is: running 07.09.2023-16:39 - DEBUG [modules.inc:240] - Processed datalog_id 901 07.09.2023-16:39 - DEBUG [plugins.inc:118] - Calling function 'ssl' from plugin 'apache2_plugin' raised by event 'web_domain_update'. 07.09.2023-16:39 - DEBUG [plugins.inc:118] - Calling function 'update' from plugin 'apache2_plugin' raised by event 'web_domain_update'. 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: chattr -i '/var/www/clients/client2/web2' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: chattr +i '/var/www/clients/client2/web2' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: df -T '/var/www/clients/client2/web2'|awk 'END{print $2,$NF}' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: which 'setquota' 2> /dev/null - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: setquota -u 'web2' '0' '0' 0 0 -a &> /dev/null - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: setquota -T -u 'web2' 604800 604800 -a &> /dev/null - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: chattr -i '/var/www/clients/client2/web2' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: usermod --groups sshusers 'web2' 2>/dev/null - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: chattr +i '/var/www/clients/client2/web2' - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: which 'apache2ctl' 2> /dev/null - return code: 0 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: which 'apache2ctl' 2> /dev/null - return code: 0 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:1891] - Writing the vhost file: /etc/apache2/sites-available/celluledev.fr.vhost 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: which 'apache2ctl' 2> /dev/null - return code: 0 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:3462] - Writing the PHP-FPM config file: /etc/php/7.4/fpm/pool.d/web2.conf 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:3471] - Removed PHP-FPM config file: /etc/php/7.3/fpm/pool.d/web2.conf 07.09.2023-16:39 - DEBUG [services.inc:56] - Calling function 'restartPHP_FPM' from module 'web_module'. 07.09.2023-16:39 - DEBUG [system.inc:2082] - Trying to use Systemd to restart service 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: systemctl is-enabled 'php7.3-fpm' 2>&1 - return code: 0 07.09.2023-16:39 - DEBUG [web module.inc:316] - Restarting php-fpm: systemctl reload php7.3-fpm.service 07.09.2023-16:39 - DEBUG [services.inc:56] - Calling function 'restartPHP_FPM' from module 'web_module'. 07.09.2023-16:39 - DEBUG [system.inc:2082] - Trying to use Systemd to restart service 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: systemctl is-enabled 'php7.4-fpm' 2>&1 - return code: 0 07.09.2023-16:39 - DEBUG [web module.inc:316] - Restarting php-fpm: systemctl reload php7.4-fpm.service 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:2009] - Apache status is: running 07.09.2023-16:39 - DEBUG [services.inc:56] - Calling function 'restartHttpd' from module 'web_module'. 07.09.2023-16:39 - DEBUG [system.inc:2082] - Trying to use Systemd to restart service 07.09.2023-16:39 - DEBUG [system.inc:2429] - safe_exec cmd: systemctl is-enabled 'apache2' 2>&1 - return code: 0 07.09.2023-16:39 - DEBUG [web module.inc:246] - Restarting httpd: systemctl restart apache2.service 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:2012] - Apache restart return value is: 0 07.09.2023-16:39 - DEBUG [apache2 plugin.inc:2023] - Apache online status after restart is: running 07.09.2023-16:39 - DEBUG [modules.inc:240] - Processed datalog_id 902 07.09.2023-16:39 - DEBUG [server:217] - Remove Lock: /usr/local/ispconfig/server/temp/.ispconfig_lock finished server.php.