WordPress

“There has been a critical error on this website.”

Your site is white. Your visitors see nothing. Below is what that message means and the four things to try right now, in order, from the least scary to the most. Then the part where you stop doing this at 2am.

No sign-up needed to use the steps below. They work whether or not you ever install anything of ours.

Right now

Four things to try, in this order.

Work down the list. Most critical errors are gone by step two. Do not skip to editing files until you have tried the first two — they are reversible, and file edits are where people turn a broken site into a lost one.

One rule before you start: if your host offers a snapshot or a one-click restore point, take one. It costs a minute and it is the difference between an annoying evening and a very bad one.

1. Check the email WordPress just sent you

Since WordPress 5.2, a fatal error triggers an automatic email to your admin address, subject line “Your Site is Experiencing a Technical Issue”. It names the plugin or theme that broke and carries a recovery-mode link.

That link logs you into wp-admin with the offending plugin paused, even though the front end is dead. Check spam. If the email never arrived, your site probably cannot send mail either — go to step 2.

2. Deactivate whatever you changed last

If you can still reach /wp-admin, go to Plugins and deactivate the one you updated or installed just before this started. Nine times in ten, that is the whole fix.

Cannot remember what changed? Deactivate all plugins, confirm the site returns, then reactivate them one at a time, loading the site after each. The one that kills it is your culprit.

3. Rename the plugin folder from your file manager

Locked out of wp-admin entirely? Open your host’s file manager (cPanel, Plesk, your host’s dashboard) or connect over SFTP, go to wp-content/plugins/, and rename the suspect plugin’s folder — add -off to the end. WordPress cannot load what it cannot find, so it deactivates it and lets you back in.

Renaming the whole plugins folder disables everything at once. Rename it back after you get in, then re-enable plugins one by one from wp-admin. If the site is still broken with every plugin off, switch to a default theme like Twenty Twenty-Four the same way.

4. Read the actual error

Everything above is guesswork until you see the real message. 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 your site, then open wp-content/debug.log. The last PHP Fatal error line names the exact file and line number. Turn WP_DEBUG back off when you are done — leaving it on can leak paths to visitors.

If none of that worked

You are into wp-config errors, a corrupted core file, a PHP version your theme does not support, or a database that will not connect. At that point restore your host’s most recent snapshot and take the diagnosis with you — the line from debug.log is worth more to whoever helps you next than any description of what the screen looks like.

The pattern

It is almost never your fault.

A WordPress site runs code from dozens of authors who have never spoken to each other, and it updates itself. Four things cause nearly every critical error:

A plugin update

The most common cause by a wide margin. An update ships a function your PHP version does not have, or clashes with another plugin that was fine yesterday.

A PHP version bump

Your host upgrades PHP for security. An older theme or plugin uses syntax that was removed, and the site dies on the next request.

Two plugins disagreeing

Both hook the same thing, or both declare the same function name. Neither is broken alone. Together they are fatal, and only on some pages.

A theme edit

One stray character in functions.php. The built-in editor will happily save a file that takes the whole site down, with no undo.

Notice what they have in common: they all happen when you are not looking. The update runs overnight, the host bumps PHP on a Tuesday, and you find out from a customer.

What Patcherly does

A plugin that still works when the site does not.

Here is the awkward truth about every WordPress tool: a fatal error stops all plugins, including the one that was supposed to help. Patcherly ships a second, tiny piece called Emergency Rescue that WordPress loads before regular plugins. So when your site white-screens, it is still running.

It sees the crash you cannot

Rescue catches PHP fatals during plugin load — before your normal error log might record them — and sends the line to your dashboard. You get told, instead of finding out from a customer.

It can roll back a dead site

Rescue picks up rollback requests from the dashboard and restores files from the backups sitting on your own server — even though nothing else on the site can run.

It applies the fix you approved

Same backup, same syntax check, same verification as the normal path. You press approve from your phone; Rescue does the work on the server.

What a fix actually looks like

  1. The error arrives. Message, file, line number, and the few lines around it.
  2. You get an explanation in plain English — what broke and why — with a confidence score, not just a diff.
  3. You approve, reject or ignore. Nothing moves until you decide. New sites start in dry run.
  4. It backs up first, into wp-content/uploads/patcherly/backups/ on your server, and syntax-checks the file before and after.
  5. It verifies the site still loads. If the check fails, rollback runs.

How approvals work →  ·  How rollback works →

Before you install anything

What it will and will not touch.

You are about to give something permission to edit files on a site that pays your bills. You should know exactly where the edge of that permission sits, before you decide.

Full detail on the security page and in the WordPress connector docs.

It can change

  • PHP files — .php and .phtml
  • Theme files and plugin files
  • Your own custom PHP
  • Core files, if the file is writable

It never touches

  • Your database or any content in it
  • Your media library and uploads
  • Your users or their data
  • JavaScript and CSS files

And three limits worth knowing

The WordPress plugin never runs commands on your server — a plugin-directory rule and a safety feature, which means no post-fix test runs or app restarts on WordPress. Rescue cannot help if PHP dies inside wp-config.php, if another must-use plugin crashes before it, or if you deleted the local backup folder. And Patcherly is not an uptime monitor — it reacts to errors your site produces, it does not ping you every minute to say the site is alive.

The honest comparison

Or you could pay someone.

Plenty of people will fix this for you, and sometimes that is the right call — a freelancer who knows your site is worth every euro on a gnarly custom build. Here is the trade, without the spin.

  Freelancer or fix service Patcherly
Clock starts whenYou notice, and write the ticketThe error happens
Typical first responseHours, or next business dayA drafted fix waiting for you
Cost shapePer hour or a monthly retainerFlat, and there is a free plan
Who gets your admin loginThey doNobody
Who decides what changesUsually themYou, every time
UndoAsk, and wait againOne click, from your own backup
Understands your custom buildA good one, deeplyReads the error, not your business

The honest version: Patcherly is very good at the boring fatal errors that make up most of your downtime, and it is not a substitute for a human on a genuinely hard problem. What it does do is hand that human a diagnosis instead of a screenshot.

Fair questions.

Still unsure? Ask us directly — the founder reads every message.

What does "There has been a critical error on this website" actually mean?

It means PHP hit a fatal error and stopped, so WordPress had nothing left to render. The cause is almost always a plugin, a theme, or a PHP version change — not your content, and not your database. WordPress hides the detail from visitors on purpose; the real message is sitting in your error log.

Can I fix a WordPress critical error without a developer?

Usually yes. Recovery mode, deactivating the plugin you just updated, or renaming the plugin folder resolves most of them, and the steps on this page cover all three. What a developer buys you is speed and the confidence not to make it worse — which is also what an approval gate and a one-click rollback buy you.

Does Patcherly work when my site is completely down?

That is what Emergency Rescue is for. It is a must-use plugin that WordPress loads before regular plugins, so it keeps logging errors, applying fixes you approve, and running rollbacks even when the main Patcherly plugin cannot load. It cannot help if PHP dies inside wp-config.php, if another must-use plugin crashes first, or if you deleted the local backup folder.

Will Patcherly change my site without asking?

Not unless you turn that on yourself. New targets start in dry run and every fix waits for your approval. Auto Apply is opt-in, scoped to a single site, and revocable in one click.

Do you get access to my WordPress admin or my database?

No. Nobody at Patcherly logs into your site. The plugin sends the error message, the file path and line, a small snippet around the error, and your WordPress and PHP versions. It never sends your database, your media library, your users, or your full site files.

What happens if the fix makes things worse?

The plugin snapshots every file in the patch into wp-content/uploads/patcherly/backups/ on your own server before it writes anything, and checks the file for syntax errors before and after. If the health check fails, rollback restores from that local backup — and you can trigger a rollback yourself at any time from the dashboard.

Which files can it actually change?

PHP files only — .php and .phtml, in your themes, plugins and custom code. It does not touch JavaScript, CSS, your database, or your uploads. If the bug is in a stylesheet or a database row, Patcherly is the wrong tool and will tell you so.

Does it work on WordPress Multisite?

Yes, including network installs, custom themes, and any plugin. Post-apply test runs and app restarts are the one exception — the WordPress plugin never executes commands on your server, which is both a plugin-directory rule and a deliberate safety limit.

Next time, find out before your customers do.

Install the plugin, click Connect, choose whether to share site context. About two minutes, no credentials change hands, and there is a demo mode if you want to see the whole workflow before you pair anything.

Full Pro plan for 30 days. No credit card. Free Personal plan after that, for as long as you like.

Running a shop? The WooCommerce page covers what a broken checkout costs and how fast this closes it.

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