Fix Critical Error on This Website in WordPress

ワードプレス powers millions of websites worldwide, from personal blogs to large e-commerce platforms. While it is one of the most flexible and user-friendly website systems available, users occasionally encounter frustrating technical messages.

One of the most common errors is:

“「このウェブサイトに重大なエラーが発生しました。」”

If you have ever opened your WordPress site only to see this message, you may have wondered what went wrong and how to fix it. The good news is that this error is usually fixable, and understanding the causes can help prevent it from happening again.

In this guide, we’ll explain what “there has been a critical error on this website. wordpress” means, why it occurs, and the most effective ways to resolve it—even if you are not a developer.

What Does “There Has Been a Critical Error on This Website” Mean?

The message “there has been a critical error on this website. wordpress” appears when WordPress encounters a fatal PHP error that prevents the site from loading correctly.

Instead of displaying a blank white screen (which used to happen in older WordPress versions), WordPress now shows this message to indicate something has gone wrong in the system.

This error typically occurs when:

• A plugin causes a conflict
• A theme contains broken code
• WordPress files become corrupted
• PHP memory limits are exceeded
• A recent update introduces compatibility issues

When WordPress detects a fatal issue, it stops execution to prevent further damage to the website.

Common Causes of WordPress Critical Errors

Understanding the root cause makes it easier to fix the problem quickly. Below are the most common reasons this error appears.

1. プラグインの競合

Plugins extend WordPress functionality, but poorly coded or incompatible plugins can cause fatal errors.

これは次のような場合によく発生します:

• A plugin is outdated
• A plugin conflicts with another plugin
• A plugin is incompatible with your WordPress version
• A plugin requires a newer PHP version

For example, installing a new plugin or updating one right before the error appears is a strong indication that the plugin might be the problem.

2. テーマの問題

Your WordPress theme controls how your website looks and functions.

If a theme contains broken code or conflicts with WordPress core updates, it may trigger the critical error on this website WordPress message.

This often occurs when:

• カスタムコードが誤って追加されました
• The theme is outdated
• The theme is incompatible with the latest WordPress version

3. Corrupted WordPress Core Files

Sometimes WordPress files become corrupted during an update or due to server issues.

This can cause the system to fail during execution, leading to the critical error message.

4. PHP Memory Limit Problems

WordPress runs on PHP, and each website has a memory allocation limit.

If a script requires more memory than the server allows, WordPress may stop running and display the critical error message.

This can occur when:

• Large plugins are installed
• Complex themes are used
• The site handles high traffic

5. Failed Updates

Updating WordPress, plugins, or themes is essential for security and performance. However, if an update fails midway due to a server interruption or compatibility issue, it can break the site.

This may cause WordPress to show the critical error message instead of loading the website.

How to Fix “There Has Been a Critical Error on This Website” in WordPress

Fortunately, several troubleshooting steps can help resolve the issue.

Below are the most practical solutions.

1. Check Your Email for Recovery Mode

Modern WordPress versions send an automatic email to the site administrator when a critical error occurs.

This email usually contains:

• 問題の原因となっているプラグインまたはテーマ
• 特別なリカバリモードのログインリンク
• Instructions for resolving the problem

Using Recovery Mode, you can log into WordPress even when the site is broken and disable the problematic plugin or theme.

2. Disable All Plugins

If you suspect a plugin conflict, disabling plugins is often the fastest way to identify the issue.

You can do this through FTP or your hosting file manager.

手順:

1. Access your website files
2. Navigate to the wp-content folder
3. Rename the plugins folder to something like:

plugins-disabled

This will deactivate all plugins at once.

If the website starts working again, you can rename the folder back and activate plugins one by one to find the faulty one.

3. Switch to a Default WordPress Theme

If the issue is caused by your theme, switching to a default WordPress theme can help.

手順:

1. Go to wp-content/themes
2. アクティブなテーマフォルダの名前を変更する
3. WordPress will automatically switch to a default theme such as:

• Twenty Twenty-One
• Twenty Twenty-Two
• Twenty Twenty-Three

If the website loads normally after this change, the theme likely caused the problem.

4. Enable WordPress Debug Mode

Debug mode allows WordPress to display detailed error messages that reveal the source of the issue.

To enable it, edit the wp-config.php file and add the following lines:

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

After enabling debug mode, reload your website.

WordPress may show the exact file or plugin responsible for the error.

Once troubleshooting is complete, it is recommended to disable debug mode again.

5. Increase PHP Memory Limit

If the problem is related to insufficient memory, increasing the PHP memory limit may resolve it.

Edit wp-config.php and add:

'WP_MEMORY_LIMIT'、'256M'を定義します。;

This increases the amount of memory available to WordPress.

6. Reinstall WordPress Core Files

If core files are damaged, reinstalling WordPress can restore missing or corrupted files.

手順:

1. Download the latest WordPress version
2. Upload the wp-admin and wp-includes folders
3. Replace the existing ones

Make sure not to overwrite the wp-content folder, which contains your themes, plugins, and uploads.

7. Contact Your Hosting Provider

Sometimes the error is caused by server-level issues, such as:

• PHP configuration problems
• Database issues
• Hosting resource limits

In these cases, contacting your hosting provider may be necessary. They can review server logs and identify the exact cause.

Preventing Critical Errors in WordPress

While errors cannot always be avoided, following best practices greatly reduces the risk.

Keep WordPress Updated

Regularly updating:

• WordPress core
• プラグイン
• テーマ

helps maintain compatibility and security.

Use Trusted Plugins and Themes

Install plugins and themes only from reputable developers or official marketplaces.

Poorly coded extensions are one of the leading causes of critical errors.

Create Regular Backups

Backups ensure that your website can be restored quickly if something breaks.

Many hosting providers offer automatic backups, or you can use backup plugins.

Test Changes on a Staging Site

Before making major updates or installing new plugins, test them on a staging environment.

This prevents issues from affecting your live website.

Why This Error Matters for Online Businesses

For businesses running WordPress stores or service websites, downtime can mean:

• 失われたトラフィック
• Reduced sales
• Lower search rankings
• Damaged customer trust

This is especially important for e-commerce and international websites, where stability and performance directly affect conversions.

A well-designed and properly maintained website significantly reduces the risk of technical failures.

最後に

The message “there has been a critical error on this website. wordpress” can seem alarming, but it usually indicates a manageable issue such as plugin conflicts, theme problems, or server configuration limits.

By identifying the root cause and following structured troubleshooting steps—like disabling plugins, switching themes, enabling debug mode, or increasing memory—you can restore your website quickly.

Maintaining a stable WordPress website requires more than just fixing errors. It also involves thoughtful design, performance optimization, and a clear structure that ensures your site runs smoothly as your business grows.

で エアサン, we specialize in helping brands build professional websites for global markets. Our team focuses on conversion-driven website design, Shopify そして ワードプレス store experiences, and cross-border e-commerce solutions that help businesses present their products clearly and effectively.

If you are building or improving your website and want a design that is both visually compelling and technically reliable, エアサン is here to help. Our experience in international website design ensures your brand stands out while maintaining a stable, high-performance online presence.