Record the exact domain, request path, time, method and safe reproduction steps. Do not collect customer passwords or unnecessary request bodies. A customer may need support to inspect server audit logs or create a narrowly scoped exception.

1. Find the matching website error and ModSecurity audit event. Record the rule ID, message and request identifier where available.
2. Confirm the blocked operation is expected application behaviour and review whether the payload indicates a real vulnerability or compromised client.
3. Check the application and rule-set versions for a supported correction. A code fix or vendor rule update may be preferable to an exception.
4. If an exception is justified, have the authorized administrator scope it to the necessary rule and affected domain or request context using the supported Plesk/ModSecurity configuration. Avoid disabling the entire firewall across the server.
5. Reproduce the harmless legitimate action once, then inspect the new audit result. Keep a record of the exception reason, owner and review date.

Confirm the intended operation succeeds and protection remains active for the rest of the domain. Test related inputs that should still be rejected through an approved non-destructive test process, not by attacking live customer data.

If there is no matching rule event, investigate filesystem permissions, application authorization, proxy rules and account status. A temporary detection-only mode changes enforcement and requires a controlled scope and restoration plan. Remove the exception when the application or rule set is corrected. Never publish complete audit logs that expose cookies, tokens or private request content.

• Diagnosing website errors with the Plesk log browser
• Adding supported Apache and nginx directives in Plesk
• Investigating a blocked IP in Plesk Fail2Ban
• Diagnosing an IIS application pool that keeps stopping

• Plesk: Web Application Firewall Modsecurity