“There Has Been a Critical Error on This Website”: What It Means and What to Do

“There has been a critical error on this website.” It’s one of the most alarming messages a site owner can see — and one of the more fixable ones. It means WordPress hit a fatal PHP error and stopped rather than show a broken page.

Your content isn’t gone. Something in the code — almost always a plugin or theme — failed, and the job is to find which one.

What the message means

Since version 5.2, WordPress catches fatal errors and shows this message instead of a blank white screen. Behind the scenes it tries to identify the plugin or theme responsible and emails the site’s administration address with details and a special link to recovery mode.

Step 1: check for the recovery mode email

Look in the inbox — and spam folder — of the email address set under Settings → General. The message names the extension that caused the error and contains a link that lets you log in with that extension paused. From there you can deactivate it, check for an update, or switch themes.

Step 2: turn on the debug log

If the email didn’t arrive, the debug log tells you what failed. Add these lines to wp-config.php, above the line that says “That’s all, stop editing”:

define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );

Reload the page, then open wp-content/debug.log. Look for the line that starts with “PHP Fatal error” — the path in it usually points to a folder inside wp-content/plugins/ or wp-content/themes/.

Step 3: deactivate the cause

Once you know the culprit, deactivate it. Without dashboard access, you can:

• Use WP-CLI: wp plugin deactivate plugin-folder-name, or switch to a default theme with wp theme activate.
• Rename the folder via SFTP: renaming a plugin’s folder makes WordPress deactivate it.

When it’s a memory error

If the log says “Allowed memory size exhausted”, the site ran out of PHP memory. Raising the limit can get it running again, but it treats the symptom: a sudden jump in memory use usually points to a heavy plugin, a large import or a loop in custom code worth investigating.

Step 4: clean up and prevent a repeat

1. Switch debug mode off again once you’ve found the cause.
2. Check key pages, forms and — for stores — the checkout.
3. Decide whether to roll back the plugin, wait for a fix, or replace it.
4. Check your PHP version; incompatibilities often surface after a server upgrade.
5. Make sure uptime and SSL monitoring is in place, so the next outage reaches you before your visitors do.

If this happened right after updates, our guide to a site broken after an update covers the next steps in more detail.

Frequently asked questions