If you’ve ever opened your WordPress website and been greeted by a message saying “There has been a critical error on this website”, you’re not alone.

The WordPress critical error is one of the most confusing and stressful problems site owners face—especially for non-technical users, business owners, or cross-border sellers who rely on their website for traffic and revenue.

This article explains the WordPress critical error in plain English.
We’ll cover what it is, why it happens, how to fix it safely, and—most importantly—how to prevent it from happening again.

No unnecessary jargon. Just clear explanations and practical guidance.

Lỗi nghiêm trọng trong WordPress là gì?

A WordPress critical error occurs when WordPress encounters a fatal PHP error that prevents the website from loading properly.

Instead of displaying broken layouts or partial content, WordPress stops execution entirely to avoid further damage. That’s why visitors may see:

• A white screen
• A generic “critical error” message
• Or no visible content at all

Since WordPress 5.2, the platform includes a built-in fatal error protection system, which replaces the old “white screen of death” with a clearer message and sometimes an admin recovery email.

Vì sao WordPress hiển thị thông báo “Lỗi nghiêm trọng”

At its core, WordPress is powered by PHP.
When PHP code fails in a way that WordPress cannot safely recover from, a critical error is triggered.

These errors typically come from customizations, plugins, or themes, not WordPress core itself.

Những nguyên nhân phổ biến nhất gây ra lỗi nghiêm trọng trong WordPress

Let’s break down the most frequent reasons this issue appears.

1. Plugin Conflicts or Bugs

Plugins are the #1 cause of WordPress critical errors.

This often happens when:

• A plugin update introduces incompatible code
• Hai plugin xung đột với nhau
• A plugin is not compatible with your PHP version
• A plugin uses deprecated WordPress functions

Page builders, performance plugins, security plugins, and e-commerce extensions are especially common triggers.

2. Theme Issues and Theme Updates

Themes can also cause fatal errors, especially when:

• A theme update removes or changes required functions
• Custom code is added incorrectly to functions.php
• A child theme is missing dependencies

If your site crashes right after changing or updating a theme, this is a strong signal.

3. Sự không tương thích phiên bản PHP

Your hosting server runs a specific PHP version.

Nếu như:

• PHP is updated automatically by the host
• Your plugins or theme don’t support the new version

WordPress may fail instantly.

Many older plugins still rely on outdated PHP syntax, which modern PHP versions reject.

4. Hết hạn mức bộ nhớ

WordPress requires memory to run scripts.

A critical error may occur if:

• Too many plugins load at once
• A heavy page builder runs complex layouts
• WooCommerce processes large queries

When PHP memory is exhausted, execution stops.

5. Corrupted Core Files or Incomplete Updates

Interrupted updates can leave WordPress in an unstable state.

This can happen due to:

• Server timeouts
• Connection drops
• Insufficient file permissions

As a result, essential core files may be missing or corrupted.

6. Incorrect Custom Code

Adding code manually—whether in a theme file, custom plugin, or snippet manager—can easily cause fatal errors if syntax is incorrect.

Even a missing semicolon can break the entire site.

How WordPress Helps You Recover from Critical Errors

Modern WordPress includes a recovery mode.

When a critical error occurs:

• WordPress sends an email to the site admin
• The email includes a secure recovery link
• This link allows you to log in and disable the problematic plugin or theme

This feature has made troubleshooting significantly easier compared to older versions.

Hướng dẫn từng bước: Cách khắc phục lỗi nghiêm trọng trong WordPress

Here’s a safe, structured approach.

Bước 1: Kiểm tra email khôi phục

Always start by checking your admin email inbox.

If WordPress detected the issue, it will tell you:

• Which plugin or theme caused the error
• How to access recovery mode

This is often the fastest fix.

Step 2: Disable All Plugins (If Needed)

If you can’t access wp-admin:

1. Log in to your hosting file manager or FTP
2. Navigate to /wp-content/
3. Đổi tên plugin folder (e.g., plugins_old)

Thao tác này sẽ vô hiệu hóa tất cả các plugin cùng một lúc.

If the site loads, the issue is plugin-related.

Step 3: Reactivate Plugins One by One

Đổi tên thư mục trở lại thành plugin, then:

• Activate plugins individually
• Refresh the site after each activation

When the error returns, you’ve found the culprit.

Bước 4: Chuyển sang giao diện mặc định

If plugins aren’t the issue:

• Đổi tên thư mục chủ đề đang hoạt động của bạn.
• WordPress sẽ tự động chuyển sang giao diện mặc định.

If the site works again, the theme is responsible.

Step 5: Check PHP Version Compatibility

Inside your hosting panel:

• Try switching to a different PHP version
• Test commonly supported versions like PHP 8.0 or 7.4

Many WordPress environments stabilize immediately after this change.

Step 6: Increase PHP Memory Limit

Low memory is a silent killer.

Bạn có thể tăng dung lượng bộ nhớ bằng cách chỉnh sửa wp-config.php:

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

This helps with complex sites and page builders.

Step 7: Enable Debug Mode for Deeper Insight

For persistent issues, enable debugging:

define(‘WP_DEBUG’, true);
define(‘WP_DEBUG_LOG’, true);
define(‘WP_DEBUG_DISPLAY’, false);

Then review the error logs to identify exact causes.

How to Prevent WordPress Critical Errors Long-Term

Fixing the issue is one thing. Preventing it is what really matters.

1. Use Quality Plugins Only

Tránh xa:

• Các plugin bị bỏ rơi
• Poorly reviewed tools
• Plugins updated years ago

Stick to actively maintained, well-supported plugins.

2. Always Test Updates

Never update directly on a live business website.

Sử dụng:

• Staging environments
• Backup snapshots

This is especially important for cross-border e-commerce sites.

3. Keep PHP, WordPress, and Plugins Aligned

Compatibility matters more than “latest version”.

A stable setup beats a bleeding-edge one.

4. Avoid Random Code Snippets

Copy-pasting code from forums without understanding it is risky.

One bad snippet can cause a full site outage.

5. Choose Professional Hosting

Cheap hosting often lacks:

• Proper PHP controls
• Error logging
• Rollback tools

Reliable infrastructure dramatically reduces fatal errors.

Why WordPress Critical Errors Are Especially Dangerous for Cross-Border Businesses

For international sellers, a broken website doesn’t just mean downtime.

It can mean:

• Lost ad traffic
• Broken payment flows
• SEO ranking drops
• Damaged brand trust

That’s why technical stability and structured design are not optional—they’re business foundations.

Final Thoughts: Don’t Just Fix Errors—Build Stable Systems

A WordPress critical error is rarely “random”.

It’s usually a sign of:

• Poor plugin architecture
• Unplanned updates
• Lack of technical oversight

With the right structure, most critical errors are completely avoidable.

Giới thiệu về AIRSANG

Tại AIRSANG, we specialize in cross-border websites built for stability, scalability, and long-term growth.

From WordPress site architecture and performance optimization
to e-commerce design and international business workflows,
we help brands avoid problems like WordPress critical errors before they happen.

If your website is critical to your business—and especially if you operate globally—
AIRSANG is here to help you build it right from the start.