Symptoms
After logging in to Plesk or switching between "Power user" and "Service Provider" views, the following error message appears in a web-browser:
ERROR: require_once(): Failed opening required 'modules/firewall/FwConfigurator.php' (include_path=<...>
Cause
Plesk Firewall installation is corrupted.
Resolution
Reinstall Plesk Firewall:
1.Connect to the Plesk server via SSH.
2.Remove Plesk Firewall:
#plesk installer remove --components psa-firewall
3.Install Plesk Firewall back:
#plesk installer add --components psa-firewall