Symptoms- All websites show a 502 Bad Gateway error
- Switching to the Atomic Standard ruleset resolves the problem
- The Plesk UI shows the following error message:
AH00526: Syntax error on line 6035 of /etc/httpd/conf/modsecurity.d/rules/comodo_free/30_Apps_OtherApps.conf: Error creating rule: Error compiling pattern (offset 4): invalid range in character class
CauseThe mod_security package installed from the Atomic repository is not fully compatible with the current Comodo rule set.
Resolution- Connect to the Plesk server via SSH.
- Execute the command to replace the ModSecurity package with the version provided by Plesk:
# dnf swap mod_security mod_security --enablerepo=PLESK_18_0_70-extras --disablerepo=atomic --skip-broken