WordPress : How to fix the WordPress Critical error

Seeing the message “Critical error” on your WordPress site can be worrying.

A critical error can prevent visitors from accessing part or all of the site. This guide helps you identify the cause and work through practical troubleshooting steps. Start with the simpler checks, and use the linked guides when more detailed instructions are needed.

Check your email for a recovery link

When WordPress detects a fatal error, it may send a message to the site administrator containing a special link to enter Recovery Mode.

• Look for a subject such as: Your site is experiencing a technical issue

• Use the valid recovery link to sign in

• WordPress may identify the affected plugin or theme so you can disable it

Did not receive the email? Check the administrator’s mailbox and spam folder. Recovery Mode requires the valid link and token supplied by WordPress; entering a recovery-mode action URL manually is not a substitute. If no link is available, use the file-based troubleshooting steps below or contact support.

Enable debugging to identify the error

If recovery access is unavailable, temporarily configure WordPress debugging to gather error details. Follow these steps:

• Access site files using an FTP client or the File Manager in your cPanel account

• Open wp-config.php in the public_html

• Set WP_DEBUG to true and enable WP_DEBUG_LOG if you want logging. Set WP_DEBUG_DISPLAY to false on a public site so errors are not shown to visitors. Edit existing definitions instead of adding duplicates.

• Save the file and reproduce the error

With WP_DEBUG_LOG enabled, WordPress can write details to wp-content/debug.log. Use the log to identify the failing plugin, theme or setting. Protect logs from public access and turn debugging off after diagnosis.

Disable plugins

Plugin errors or conflicts can cause a critical error. Test by temporarily disabling plugins:

• Open the directory /wp-content/

• Rename the plugins directory, for example to plugins_old

• Reload your site

If access returns, a plugin may be involved. Restore the directory name to plugins, then activate plugins individually from WordPress administration, checking the site after each one. The plugin that triggers the error needs investigation.

Switch to a default theme

If disabling plugins does not resolve the error, test the active theme. To do this:

• If you can access administration, open Appearance > Themes and activate an installed default theme, such as Twenty Twenty‑Four

• If administration is unavailable, open /wp-content/themes/ and consider renaming the active theme’s directory after making a backup and ensuring a usable default theme is installed.

WordPress can fall back to an installed default theme, but this is not guaranteed if none is available. If the site works with the replacement theme, investigate the original theme.

Review the PHP memory limit

A script that exceeds available PHP memory may fail with a critical error. Check logs before increasing limits. See our detailed guide: How to change PHP option values

Reinstall WordPress core files

WordPress core files can become incomplete or damaged during an update or transfer. For instructions on verifying or reinstalling core files while preserving content, see: Reinstall core files with WP Toolkit

Restore a site backup

If you use one of our shared hosting plans, check the backups available in JetBackup for your account and their dates. Select a known working backup and consider what newer data would be overwritten. Our guide explains the restoration process: How to back up and restore your hosting account

Other checks

If the error persists, also review these points:

• Clear site and browser caches to rule out a cached error page.

• Check that PHP is a supported version compatible with your WordPress installation, plugins and theme. See this guide for changing PHP versions in cPanel.

• Review server error logs. Depending on the application’s configuration, an error_log file may be accessible through File Manager > public_html > error_log.

Good practices to prevent future errors

After resolving the issue, take these steps:

• Test updates safely : use a staging site before applying theme or plugin changes to production

• Install from trusted sources : review plugin and theme quality, maintenance and compatibility

• Monitor error logs : use debugging in a protected test environment

A critical error often involves a plugin, theme, failed update or configuration problem. The checks above help narrow down the cause so you can repair it or provide useful details to support. Still unable to restore access? Contact our support team for further help.