Short answer
It is WordPress’s way of saying a fatal PHP error stopped the page from being built. The message deliberately hides the detail from visitors — the actual cause is in the PHP error log, or in the email WordPress sends to the admin address.
A plugin or theme update is the usual trigger. If you cannot get into wp-admin, renaming the plugins folder over FTP disables all of them at once and almost always gets the site back, after which you can re-enable them one at a time to find the culprit.
Learn more
- “There has been a critical error on this website”What WordPress’s critical error message means, how to use recovery mode, and how to find and disable the plugin or theme causing it.
- How to find PHP errors (error logs and display_errors)Where PHP errors are recorded on Traxio, how to log errors without showing them to visitors, and how to set up logging for a custom application.
- How to turn on WordPress debugging safelyUse WP_DEBUG, WP_DEBUG_LOG and WP_DEBUG_DISPLAY to see WordPress errors without showing them to visitors, and turn debugging off afterwards.
Step-by-step
- Fix a WordPress critical error without admin accessIntermediate · 20 min · 7 steps