The WordPress critical-error message means a fatal error prevented WordPress from completing the request. Common causes include plugin/theme failures, incompatible PHP code, memory exhaustion, or damaged files.
- Check whether WordPress sent a Recovery Mode email to the site administrator address.
- If Recovery Mode is available, log in through that special link and review the component WordPress paused or identified.
- If no recovery message is available, enable WordPress debug logging while keeping error display off for public visitors.
- Review your configured protected debug log and cPanel Errors for the first fatal error.
- Reverse the plugin, theme, PHP, or code change implicated by the log.
After resolving the problem, disable production debugging and confirm the frontend and wp-admin both work normally.
Protect the log itself, not just error display. Follow Using WordPress Debug Logging Without Exposing Errors to Visitors for a private log location; do not leave a publicly downloadable debug.log.
Documentation for this guidance: developer.wordpress.org — debug wordpress.
