- Plesk for Linux
Pre-upgrade checker shows the following warning if a custom ModSecurity is installed on a server:
Warning: WARNING: You have already installed mod_security package which is not from Panel distribution. You should deinstall package mod_security before component 'modsecurity' installation, otherwise, your apache web-server will be broken. Check KB article for details http://kb.plesk.com/122324
A custom ModSecurity is installed on a server, but ModSecurity shipped with Plesk was never installed previously.
This is a warning only that can be skipped. If Plesk ModSecurity shipped by Plesk was never installed, upgrade should be completed smoothly.
To prevent any possible issues related to the fact that custom ModSecurity interacts with Apache configuration files that are modified during Plesk upgrade, remove custom ModSecurity and start the upgrade.