Quick Diagnosis
Start with the most recent change. A critical error is usually a specific PHP fatal error, not a vague site-wide mystery.
Problem
There Has Been a Critical Error on This Website
Diagnose the WordPress critical error screen by checking recent plugin changes, PHP fatal errors, recovery mode, server logs, and safe rollback options.
Problem
A PHP fatal error stopped WordPress before the page could render normally.
For: WordPress site owners and agencies responding to a sudden fatal error screen.
Workflow
What to review
Safe First Move
Avoid deleting plugins or database rows. Disable the suspected component and preserve evidence for the owner or developer.
WordPress ErrorsSeverity: HighLast reviewed: 2026-09-16
Diagnosis
Symptoms, causes, checks, and fixes
Symptoms
- Public pages or wp-admin show the critical error message.
- Recovery mode may send an email to the site administrator.
- The issue often starts after an update, install, edit, or PHP version change.
Most Common Causes
- Plugin or theme fatal error.
- PHP version incompatibility.
- Memory exhaustion.
- Broken custom code.
How To Confirm The Cause
- Check the recovery mode email if available.
- Review recent plugin/theme/core updates.
- Inspect hosting PHP error logs or the WordPress debug log if safely enabled.
Fixes
- Disable the most recently changed plugin or theme from wp-admin, SFTP, or hosting tools.
- Restore the last known-good file change if custom code was edited.
- Confirm PHP version support before switching versions.
How To Verify The Fix
- Reload the affected URL.
- Open wp-admin.
- Confirm PHP logs stop recording the same fatal error.
When To Contact Support
Contact hosting support when logs are inaccessible, the site cannot be reached by SFTP, or PHP-level recovery is required.
References