How to Fix "There Has Been a Critical Error on This Website" in WordPress

You open your website and instead of your homepage there is a plain white box with one line in it: "There has been a critical error on this website." No menu, no logo, sometimes no way into the dashboard either.

It looks bad, but in most cases nothing is lost. Your pages, posts, images and orders are still sitting in the database. Something in the code that runs your site has crashed, and WordPress is hiding the technical details from visitors. This guide shows how to find what crashed and switch it off, with screenshots from a test site we broke on purpose.

What the critical error actually means

WordPress is written in PHP. When a plugin, a theme or WordPress itself calls something that does not exist, or runs out of memory, PHP stops with a "fatal error". Before WordPress 5.2 that usually meant a blank white page, the famous "white screen of death". Since 5.2, WordPress catches the crash and shows this message instead.

The message is deliberately vague, because the real error can reveal file paths on your server. The useful details are hidden, not gone. The next two steps show you where to find them.

Step 1: Check the admin email for a recovery link

When WordPress catches a fatal error, it sends an email to the site's admin address (the one under Settings › General). The subject line says your site is experiencing a technical issue, and the email names the plugin or theme that caused it.

At the bottom is a recovery mode link. It logs you into the dashboard with the faulty plugin paused for you only, so you can deactivate it, update it or replace it while visitors still see the error. The link works for one day. If the error keeps happening, WordPress sends a fresh one.

Two things often get in the way: the email lands in spam, or the site cannot send email at all. That second problem is common enough that we wrote a separate guide on WordPress not sending emails. If no email arrives, go to step 2.

Step 2: Turn on the debug log to see the real error

You need access to your site's files for this, through your hosting control panel's File Manager (cPanel, hPanel, Plesk and so on) or an FTP app.

1. Open wp-config.php in the main WordPress folder, usually public_html. Take a copy of it before you edit anything.
2. Find the line define( 'WP_DEBUG', false ); and replace it with these three lines:
   define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );
3. Save, then reload the broken page once so the error happens again.
4. Open wp-content/debug.log. The last "PHP Fatal error" line is the one you want.

Setting WP_DEBUG_DISPLAY to false keeps the error out of the page, so visitors do not see your server paths. On our test site we turned display on so you can see what the message looks like:

You do not need to understand the whole message. Look for the path. If it contains wp-content/plugins/something/, that plugin crashed. If it contains wp-content/themes/something/, it is your theme.

Step 3: Switch off the plugin or theme that crashed

If you can reach the dashboard through the recovery link, deactivate the plugin under Plugins. If you cannot log in at all, do it from the file side:

1. Go to wp-content/plugins/ in File Manager or FTP.
2. Rename the plugin's folder, for example old-gallery to old-gallery-off. WordPress can no longer find it, so it stops loading it.
3. Reload your site. It should be back. When you next open the Plugins screen, WordPress confirms it switched the plugin off.

If the error pointed at your theme, rename the theme's folder in wp-content/themes/ instead. WordPress falls back to one of its default "Twenty" themes, as long as one is still installed. Your site will look different until the theme is fixed, but it will be up.

Not sure which plugin it is and no log? Rename the whole plugins folder to plugins-off. If the site comes back, rename it back, then switch plugins off one at a time until the error returns. Slow, but it always finds the culprit.

Once the site is up, decide what to do with the plugin: update it if there is a newer version, swap it for a maintained alternative, or delete it if you no longer need it. Do not just turn it back on.

The causes we see most often

What the log says	What it usually means	Fix
Call to undefined function	An old plugin or theme uses PHP code removed in newer PHP versions, often right after the host upgraded PHP.	Update or replace the plugin. See our PHP version guide.
Allowed memory size exhausted	The site ran out of PHP memory, common with page builders and WooCommerce.	Raise the memory limit with your host, or add define( 'WP_MEMORY_LIMIT', '256M' ); to wp-config.php.
Cannot redeclare function	Two plugins (or a plugin and the theme) define the same thing, often a duplicate or an old copy left behind.	Remove the duplicate.
Class not found or failed opening required file	An update did not finish, so files are missing.	Reinstall that plugin or theme fresh from its source.
Syntax error, unexpected	Someone edited a theme file (often functions.php) and left a typo.	Undo the edit or restore that file from a backup.

How to stop it happening again

• Take a backup before every round of updates, and know how to restore it.
• Update one plugin at a time on important sites, so you know which one caused a problem.
• Test big updates on a staging copy first.
• Remove plugins you no longer use. Every plugin is code that can break.
• Keep PHP on a supported version, and check plugins work on it before your host switches.
• Make sure the admin email address is one somebody actually reads.

This is the routine our website maintenance plans follow, from $10 a month (₹1,500 in India). If your site is showing the critical error right now and you would rather not touch wp-config.php, send us your site address and we will tell you what crashed and what it takes to fix it.