"There has been a critical error on this website" — what to do

This message replaced the old white screen of death. It is more polite and equally uninformative: "There has been a critical error on this website."

Underneath it, WordPress knows exactly what went wrong. It is simply not telling you. Here is how to make it.

First, check your email

WordPress emails the site administrator when this happens, and the email contains the actual error — the file, the line number, and usually the plugin responsible.

Check the inbox for the admin email address on the site, including spam. The subject is normally "Your Site is Experiencing a Technical Issue".

That email often also contains a recovery mode link, which logs you into wp-admin with the offending plugin temporarily disabled. If you have it, use it — that is the fastest route in.

If there is no email

The email frequently does not arrive, because WordPress email is unreliable by default — and if the site is broken enough, it never sent.

So turn on logging manually. Edit wp-config.php over SFTP or your host's file manager, and add these above the line that says "stop editing":

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

Reload the site, then open wp-content/debug.log. The last entry names the file and line. The file path tells you which plugin or theme is responsible.

WP_DEBUG_DISPLAY set to false matters — it logs the error without printing it to visitors.

Turn all three off again once you are done. Leaving debug enabled in public reveals file paths and software versions.

The common causes, and what to do

A plugin conflict or a bad update

By far the most likely, especially if this started right after an update.

Fix: rename the plugin's folder in wp-content/plugins over SFTP — some-plugin becomes some-plugin-off. WordPress cannot find it, deactivates it, and the site usually returns.

If you do not know which plugin, rename the whole plugins folder to plugins-off. If the site comes back, rename it back and then rename plugins one at a time until it breaks again — that identifies the culprit.

Full recovery steps for a bad update are here.

A PHP version mismatch

Very common after a host upgrades PHP, or after updating a plugin that now requires a newer version.

The log says something like "syntax error, unexpected" or "Call to undefined function".

Fix: ask your host which PHP version you are on. If it is 7.x, you are overdue an upgrade anyway — but check the site on staging first, because very old plugins sometimes break on newer PHP.

Memory exhausted

The log says "Allowed memory size of X bytes exhausted".

Fix: add define( 'WP_MEMORY_LIMIT', '256M' ); to wp-config.php. If that does not resolve it, the server limit is lower than that and your host needs to raise it.

A theme problem

If renaming every plugin does not help, rename your theme folder in wp-content/themes. WordPress falls back to a default theme — ugly, but working, and it tells you where the problem is.

A corrupted core file

Rare, and it happens after an interrupted update. Download a fresh copy of WordPress and replace wp-admin and wp-includes entirely, leaving wp-content and wp-config.php alone.

What not to do

Do not restore a backup as your first move. You will lose everything since that backup, and the cause will still be there waiting — particularly if it was a PHP upgrade or a plugin update you will simply apply again.

Do not start deleting files you do not recognise. Rename instead; it is reversible.

Do not panic about it being a hack. A critical error is almost always a code conflict. If you actually want to check for a compromise, the signs are different.

Still stuck?

If the debug log names a file you do not recognise, or renaming plugins does not help, the problem is likely below WordPress — a server configuration change, a database connection issue, or a corrupted install.

At that point your host's support is the fastest route, and they can see server logs you cannot.

If you would rather have someone look at it, our broken site rescue is diagnosed free within four business hours and quoted before any work starts, so you are never in an open-ended bill. Most jobs land between $150 and $500, and we will tell you honestly if the answer is simpler than that.