Fix “There Has Been a Critical Error” in WordPress (Quick Guide)

Seeing this message is scary but most of the time it’s fixable in minutes.
This guide shows safe, step-by-step actions you can do even if you can’t log in.

Before you start: If your host offers one-click backups, take one now.

What this error means (in simple words)

WordPress stopped because something crashed, usually a plugin, theme, PHP version, or low memory. We’ll turn on a log to see the real reason and then fix it.

Quick safety steps (2 minutes)

1. Open your hosting File Manager (or connect via FTP/SFTP).
2. Go to your site folder (often public_html or htdocs).
3. Download a copy of wp-config.php to your computer (backup).

Step 1: Turn on debugging (to create a log)

Edit wp-config.php and add these lines above the line that says
/* That's all, stop editing! Happy publishing. */

define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false ); // keep errors off the screen

Save the file. Now visit your site again to trigger the error.
A file named /wp-content/debug.log should appear. Download and open it.

Step 2: Read the clue

Look for lines that mention a plugin, theme, or PHP Fatal error.
Examples:

• Fatal error: ... in /wp-content/plugins/some-plugin/...
• Allowed memory size exhausted
• Call to undefined function ... (often PHP version mismatch)

Use the matching fix below.

Step 3: Fix by cause

A) Plugin conflict or broken plugin

If the log shows a plugin path, or you updated/installed a plugin just before the crash:

1. In wp-content/, rename the folder plugins to plugins.off.
   Your site should load again (without plugins).
2. Rename it back to plugins, then rename only the suspected plugin’s folder (e.g., woocommerce.off) to find the bad one.
3. Update or replace that plugin. If needed, contact the plugin author.

Note: Renaming a plugin folder does not delete your data.

B) Theme conflict

If the log mentions your theme (or you edited functions.php):

1. Go to wp-content/themes/ and rename your active theme folder (e.g., yourtheme.off).
   WordPress will fall back to a default theme (Twenty Twenty-Four).
2. If site loads, the theme (or a child theme edit) is the issue.
   Revert recent edits or reinstall a clean copy.

C) Low PHP memory

If you see “Allowed memory size exhausted”:

Add these to wp-config.php (above the “stop editing” line):

define( 'WP_MEMORY_LIMIT', '256M' );
define( 'WP_MAX_MEMORY_LIMIT', '512M' );

Also raise memory in hosting if your panel allows PHP memory settings.

D) PHP version issue

A plugin/theme may require a different PHP version.

• In your hosting panel, switch PHP to a stable version supported by your stack (ask host docs).
• After switching, test the site.
• Keep WordPress, themes, and plugins updated to match supported PHP versions.

E) Corrupted core files

Very rare, but easy to fix safely:

1. Download the same WordPress version from wordpress.org.
2. Upload only the wp-admin and wp-includes folders to your site, overwrite existing ones.
3. Do not touch wp-content or wp-config.php.

E) Corrupted core files

Very rare, but easy to fix safely:

1. Download the same WordPress version from wordpress.org.
2. Upload only the wp-admin and wp-includes folders to your site, overwrite existing ones.
3. Do not touch wp-content or wp-config.php.

F) Database repair (if logs hint at DB issues)

Add this line to wp-config.php temporarily:

define( 'WP_ALLOW_REPAIR', true );

Visit https://yoursite.com/wp-admin/maint/repair.php, click Repair Database.
Remove the line afterward.

Step 4: Turn off debugging

When fixed, remove (or set to false) the debug lines you added, so the log won’t grow forever.

define( 'WP_DEBUG', false );

Delete /wp-content/debug.log if it’s large.

Restore from a backup (if needed)

If nothing works and you have a clean backup from earlier today or yesterday, restoring can be faster than hunting the issue.

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Prevent this next time

• Update safely: update one thing at a time and test.
• Staging site: try changes on a staging copy first.
• Keep backups: daily automatic backups with quick restore.
• Quality control: avoid random plugins; prefer trusted authors.
• Monitor PHP version: upgrade with plugin/theme compatibility in mind.

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Need help?

If you’re stuck, we can fix it for you, fast!

Send us:

• The last thing you changed (updated plugin/theme, code snippet, etc.)
• A copy/paste of the last 30–50 lines from /wp-content/debug.log
• Your host name and PHP version

FAQ

Can I fix this without logging into wp-admin?
Yes—use File Manager/FTP to rename plugins/themes and edit wp-config.php.

Will renaming a plugin delete data?
No. It only disables the plugin. Data stays in the database.

I don’t see debug.log.
Make sure the 3 debug lines are added correctly, visit the site again, and check file permissions on /wp-content/.

Is this a hack?
Usually not. It’s commonly a plugin/theme/PHP conflict. Still, keep everything updated and use security scanning.