How to Fix WordPress Critical Error
WordPress Troubleshooting & Fixes
How to Fix WordPress Critical Error
The “There has been a critical error on this website” message is one of the most frustrating issues in WordPress. It can lock you out of wp-admin, break your frontend, and confuse your visitors. This guide explains every cause, every fix, and how to troubleshoot step-by-step even if you are not technical.
1
Why WordPress Shows a Critical Error
The error hides the real issue—but we can uncover it.
WordPress displays a generic “critical error” message instead of showing the actual PHP error. This usually happens due to:
- Plugin conflicts or a faulty plugin update
- Theme coding errors
- PHP version incompatibility
- Corrupted WordPress core files
- Memory limit exhausted (low server resources)
- Database connection failure
- Incorrect file permissions
To fix it, we must identify the root cause.
2
Step 1: Enable WP Debug Mode to Reveal the Error
This reveals the actual cause behind the critical error.
How to enable debug mode:
Open wp-config.php via File Manager or FTP and add this above the line /* That's all, stop editing! */:
define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );
Now check the log file:
- /wp-content/debug.log
This will show error messages like:
- Plugin fatal errors
- Theme function errors
- Memory exhausted messages
- Deprecated functions
Once you know the cause, you can apply the correct fix below.
3
Step 2: Fix Plugin-Related Critical Errors
Most critical errors come from faulty plugins.
If you can’t access WordPress admin, disable plugins manually:
Method A — Rename Plugin Folder
- Open File Manager → wp-content
- Rename the folder plugins to plugins-disabled
- Your site will load without plugins
If the site loads → a plugin is the problem.
Method B — Disable Plugins Individually
- Rename the folder back to plugins
- Open the folder
- Rename plugin folders one by one
This identifies the faulty plugin.
✓
Faulty plugin deactivated safely
✓
Website accessible without breaking
✓
Find the exact source of the issue
4
Step 3: Fix Theme-Related Critical Errors
Sometimes the issue is a broken theme file or update.
Switch to a default theme (like Twenty Twenty-Four) by renaming your active theme folder.
Steps:
- Go to wp-content/themes
- Find your active theme folder
- Rename it to something like theme-disabled
- WordPress automatically switches to a default theme
If the site works → the theme was the problem.
Common theme error causes:
- PHP function errors
- Custom code snippets
- Corrupted theme update
- Incompatible PHP version
5
Step 4: Fix PHP Memory Exhausted Error
A common cause of critical errors.
Add this to your wp-config.php file:
define( 'WP_MEMORY_LIMIT', '512M' );
Or ask your host to increase memory limit if restricted.
Signs of memory issues:
- Admin dashboard crashing
- Elementor not saving
- WooCommerce pages loading slowly
6
Step 5: Replace Corrupted WordPress Core Files
Your WP installation may be damaged.
Steps:
- Download fresh WordPress from wordpress.org
- Upload files via File Manager
- Replace everything except:
- wp-content folder
- wp-config.php file
This fixes missing or corrupted core files.
7
Step 6: Fix Database Connection Issues
Critical error + “Error establishing a database connection.”
Check your wp-config.php for correct values:
- DB_NAME
- DB_USER
- DB_PASSWORD
- DB_HOST (usually localhost)
Repair the database:
Add this temporarily:
define( 'WP_ALLOW_REPAIR', true );
Then open:
yourdomain.com/wp-admin/maint/repair.php
Click “Repair Database”
Remove the line after repair.
8
Step 7: Fix File Permission Errors
Incorrect permissions block core WP files.
Correct permissions:
- Folders: 755
- Files: 644
- wp-config.php: 600 or 644
Wrong file permissions can cause critical errors during theme/plugin operations.
9
Final Step: Disable Debug Mode & Secure Your Site
Keep your site safe after fixing the issue.
Turn off debug mode:
define( 'WP_DEBUG', false );
Also ensure:
- Your plugins are updated
- Your theme is updated
- Your WordPress version is updated
- Your PHP version is 8.0 or above
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