Web Application Firewall is enabled with "Atomic ModSecurity rule set (subscription)" but does not work even when MU#52 is installed.
Rule set "Atomic ModSecurity rule set (subscription)" was enabled before installing MU#52.
Make sure the latest Plesk updates are installed:
#/usr/local/psa/admin/sbin/autoinstaller --select-release-current --reinstall-patch --upgrade-installed-components
After installing MU#52 make sure
modsecurity_get_tortix_ruleset.pycfiles are removed:
rm -f /usr/local/psa/lib/modules/python/modsecurity_get_atomic_ruleset/modsecurity_get_atomic_ruleset.pyc /usr/local/psa/lib/modules/python/pylib-modsec-atomic/plesk_atomic.pyc /usr/local/psa/lib/modules/python/modsecurity_get_tortix_ruleset/modsecurity_get_tortix_ruleset.pyc
Make sure the daily update for rule set is enabled at Tools & Settings > Web Application Firewall > Settings.
Run daily maintenance script with the following option:
# plesk php /usr/local/psa/admin/plib/DailyMaintainance/script.php -f UpdateModSecurityRuleSet daily