WordPress White Screen of Death & Critical Error: Complete Fix Guide

Your WordPress site just went blank — no error, no menu, no content, just a white screen. Or maybe it's showing "There has been a critical error on this website" instead. Both are the same underlying problem showing up differently depending on your WordPress version, and both mean visitors (and customers, if you run WooCommerce) can't see your site at all.

I've fixed this exact issue for WordPress sites across the US, UK, and Europe over my 14+ years as a WordPress developer. This guide walks through the real causes in the order you should actually check them — no guesswork, no randomly deleting plugins.

White Screen vs. Critical Error — Same Problem, Different Display

Both are caused by a PHP fatal error — WordPress simply displays it differently depending on your setup:

• White Screen of Death (WSOD) — a completely blank page, no text at all. Happens when WP_DEBUG_DISPLAY is off and no error-handling wrapper is active.
• "There has been a critical error on this website" — WordPress 5.2+ added this friendlier fatal-error message with an option to email the site admin. Same root cause, better messaging.

The fixes below apply to both — the only difference is which one your site happens to show you.

Common Causes of White Screen / Critical Error

• A plugin update that's incompatible with your PHP version or WordPress core
• A theme function causing a PHP fatal error
• PHP memory limit exhausted
• A corrupted core file or incomplete WordPress update
• A syntax error introduced by manually editing functions.php or a plugin file
• Incompatible PHP version after a server-side PHP upgrade

Step 1: Enable Debug Mode to See the Actual Error

Access your site files via FTP, cPanel File Manager, or aaPanel, and open wp-config.php. Add these lines just 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 check /wp-content/debug.log. You'll see the exact PHP error, the file, and the line number that caused the crash — this turns a guessing game into a direct fix.

Step 2: Deactivate All Plugins via File Manager

Since you can't access wp-admin, do this via FTP/File Manager instead:

• Navigate to /wp-content/plugins/
• Rename the folder to plugins-disabled
• Reload your site — if it loads now, the issue is a plugin

Rename the folder back to plugins, then rename each individual plugin folder one at a time (e.g. woocommerce → woocommerce-off) reloading the site after each, until you find the exact plugin causing the crash.

Step 3: Switch to a Default Theme

Via FTP, go to /wp-content/themes/ and rename your active theme's folder (e.g. your-theme → your-theme-off). WordPress will automatically fall back to a default theme (Twenty Twenty-Four, etc.) if one is installed. If the site loads now, your theme's functions.php or a template file has the error.

Step 4: Increase the PHP Memory Limit

Add this line to wp-config.php, above the "stop editing" line:

define( 'WP_MEMORY_LIMIT', '256M' );

If your debug log shows "Allowed memory size exhausted," this is very likely the fix — though it's often a symptom of a deeper issue (like a plugin conflict) rather than the root cause on its own.

Step 5: Restore Core Files (Incomplete Update)

Re-upload fresh WordPress core files (excluding wp-content and wp-config.php) from wordpress.org. This replaces any corrupted or partially-updated core files without touching your content, plugins, or theme.

Step 6: Check for a PHP Version Mismatch

Check your current PHP version in your hosting control panel (cPanel, aaPanel, Plesk). If it was recently changed, try reverting to the previous version temporarily to confirm — then update the incompatible plugin/theme instead of staying on old PHP long-term.

Quick Reference Checklist

How Much Does It Cost to Fix a White Screen or Critical Error?

Most of the time this is a fast fix once the actual error is identified:

• Simple plugin/theme conflict: usually resolved within 30–60 minutes of developer time
• Memory limit or config fix: under 30 minutes, often a one-line change
• Corrupted core files or failed update: 1–2 hours, including verification that nothing else broke
• Custom code conflict (functions.php, custom plugin): 1–3 hours depending on how the code was written

Since the site is completely inaccessible while this is happening, most clients want it fixed same-day — which is realistic for the vast majority of cases once someone experienced is looking at the actual error log instead of guessing.

Still Showing White Screen After All This?

If you've worked through every step above and the site still won't load, the cause is likely something deeper — a compromised file from a hack, a database-level issue, or custom code that needs an experienced eye. As a WordPress developer with 14+ years of experience, I fix these regularly, often the same day. If your site was recently hacked rather than just broken, see my guide on recovering a hacked WordPress site — the symptoms can look similar.