Hey there, fellow WordPress user! If you’ve ever logged into your site only to be greeted by that dreaded message—”There has been a critical error on this website”—you know how heart-sinking it can be. Your blog or online store suddenly goes down, visitors can’t access it, and you’re left scratching your head. I’ve been there myself a few times, usually after a plugin update gone wrong or some sneaky compatibility issue. The good news? This error is often fixable without needing to call in a developer. In this guide, I’ll walk you through the process step by step, based on what worked for me and countless others in the WordPress community.

WordPress critical errors like this typically stem from plugin conflicts, theme issues, or even server problems. But don’t panic—enabling debug mode is your first line of defense to uncover the root cause. Let’s dive in.

Critical Error Message

Step 1: Access Your wp-config.php File and Enable Debug Mode

The key to diagnosing this error is turning on WordPress’s built-in debugging tools. By default, WordPress hides detailed error messages to keep things user-friendly (and secure), but that leaves you in the dark. To flip the switch, you’ll need to edit your site’s wp-config.php file. This file is like the brain of your WordPress installation, controlling settings behind the scenes.

Here’s how to do it:

  1. Log in to your hosting control panel or use FTP. If your host uses cPanel (like many do), head to the File Manager. Look for your WordPress root directory—usually public_html or something similar. If you’re more comfortable with FTP, tools like FileZilla work great. Connect using your credentials from your hosting provider.
  2. Locate and edit wp-config.php. It’s right there in the root folder. Right-click to edit (in cPanel) or download and open it in a text editor like Notepad++.
  3. Add the debug code. Scroll down to just above the line that says “/* That’s all, stop editing! Happy publishing. */” and insert this:
// Enable WP_DEBUG mode
define( 'WP_DEBUG', true );

This tells WordPress to display errors on the screen or log them for you to review. Save the file and upload it back if you downloaded it.

Pro tip: If you want errors logged to a file instead of shown publicly (which is safer for live sites), add these lines too:

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

The log will appear in wp-content/debug.log—super handy for troubleshooting without scaring off visitors.

WP Config Debug Code

Step 2: Reload Your Site and Check the Error Details

Once debug is enabled, refresh your site. Instead of the vague “critical error” message, you should now see a more specific fatal error or warning. This is gold! It might point to a file path, line number, and even the culprit—like a plugin or theme.

For example, in one case I dealt with, the error looked something like this: a stack trace showing an undefined function in a plugin file. If it’s a plugin issue, it’ll often mention the plugin name right there.

Fatal Error Stack Trace

If the error doesn’t show on the frontend, check the debug.log file via FTP or cPanel. Open it up and scan for recent entries. Common culprits include outdated plugins, theme conflicts, or PHP version mismatches.

Step 3: Fix the Specific Issue Based on the Error

Now that you have the details, it’s time to act. Here’s how to handle some frequent scenarios:

  • Plugin Conflicts: If the error traces back to a plugin (like Contact Form 7 in my example), deactivate it temporarily. Via FTP, navigate to wp-content/plugins, find the folder (e.g., contact-form-7), and rename it to something like contact-form-7-old. Reload your site—if it works, bingo! You can then reinstall a fresh version from the WordPress repository or update it if an newer release fixes the bug.
  • Theme Problems: Similar drill—switch to a default theme like Twenty Twenty-Four. Rename your active theme’s folder in wp-content/themes to force WordPress to fallback.
  • Other Common Fixes: Update everything! Go to your WordPress dashboard (if accessible) or use auto-updates. Check your PHP version in cPanel—WordPress recommends 7.4 or higher. If all else fails, increase your site’s memory limit by adding define('WP_MEMORY_LIMIT', '256M'); to wp-config.php.

In my Contact Form 7 case, the error was due to an undefined function called wp_is_serving_rest_request() in submission.php. Turns out, it was a compatibility glitch after a WordPress update. Renaming the plugin folder got the site back up, and reinstalling the latest version sorted it out.

Preventing Future Critical Errors

Once your site is running again, take preventive steps:

  • Keep plugins and themes updated, but test on a staging site first.
  • Use reliable hosting with good backups—services like SiteGround or Bluehost make this easy.
  • Install a security plugin like Wordfence to catch issues early.

There you have it—a straightforward way to tackle that pesky WordPress critical error. If you’re still stuck, the official WordPress troubleshooting forums are a lifesaver. Drop a comment below if this helped or if you have your own tips—let’s keep our sites running smoothly!

Happy blogging! 🚀