What Does the “Critical Error” Mean?
This error occurs when PHP — the programming language WordPress runs on — encounters a fatal error that it cannot recover from. Instead of showing a blank white screen (the infamous “white screen of death”), WordPress now shows a generic error message since version 5.2+.
You might see something like:
“There has been a critical error on this website. Please check your site admin email inbox for instructions.”
Troubleshooting the Error
Step 1: Enable WP Debug Mode
To get the actual cause of the error, edit your wp-config.php file and add the following lines:
define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);
define('WP_DEBUG_DISPLAY', false);
This creates a debug log at:/wp-content/debug.log
Look in the log file for lines that mention:
- Fatal error
- Plugin names
- Line numbers
- Deprecated functions
Step 2: Check for Plugin Conflicts
In my case, the issue was caused by the LiteSpeed Cache plugin, which conflicted with how activity feeds or dynamic content were cached in BuddyBoss (a BuddyPress-based theme).
But sometimes it could be another plugin like:
- Page builders (Elementor, WPBakery)
- Security plugins
- WooCommerce add-ons
- LMS plugins like LearnDash or TutorLMS
✅ Quick Way to Isolate:
- Rename the
/plugins/folder temporarily to deactivate all plugins through FTP/SFTP. - Then rename it back and reactivate one plugin at a time.
Step 3: Purge All Caches
Caching can serve outdated or broken content. If you’re using LiteSpeed Cache or any other caching plugin:
- Go to LiteSpeed Cache > Toolbox > Purge All.
- Also purge:
- Browser cache
- Cloudflare (if used)
- Server cache via cPanel (if on LiteSpeed server)
Step 4: Temporarily Switch to a Default Theme
Switch to a theme like Twenty Twenty-Four. If the error disappears, the issue may be with your current theme or custom templates.
Why Does This Happen Randomly?
This type of error may appear intermittently because:
- Cache plugins are serving partial or broken pages.
- Plugin updates introduce new conflicts.
- PHP versions are incompatible with certain plugin code.
- Transient data or object cache corrupts output.
Even if everything looks fine in the WordPress backend, dynamic content (like activity feeds or profile pages) on the frontend may throw errors if cache stores bad data.
✅ How I Fixed It
In my case, here’s what worked:
- Deactivated LiteSpeed Cache — and the error disappeared.
- Enabled debug mode and found a conflict with a dynamic BuddyBoss activity component.
- Switched to WP Super Cache temporarily for basic caching.
- Reconfigured LiteSpeed Cache to exclude BuddyBoss-related pages from being cached (
/members/*,/groups/*, etc.). - Whitelisted necessary JS/CSS and disabled object cache on certain pages.
Recommendations
To prevent this in the future:
- Always update plugins one at a time and test the frontend.
- Use staging environments to test before pushing live.
- Consider using Query Monitor plugin to see real-time PHP errors.
- Regularly clear and reconfigure your cache settings, especially when using dynamic plugins like BuddyBoss, WooCommerce, or LMS tools.
Need Help?
Still stuck? Feel free to comment below with:
- Your WordPress version
- List of active plugins
- PHP version
- Recent changes before the error appeared
Let’s help each other troubleshoot smarter!
