How to Fix a Critical Error on WordPress: Troubleshooting Guide

Encountering a critical error on WordPress can leave you feeling stuck and unsure of where to start. You might see a puzzling message stating, “There has been a critical error on this website,” which often prevents you from accessing your WordPress admin area. Although the wording is vague, the implication is clear: something has severely disrupted your site’s usual processes.

In many instances, WordPress attempts to email the site administrator details regarding the plugin, theme, or piece of code that caused the issue. However, email notifications are not always reliable, and receiving minimal information can hinder your troubleshooting efforts.

In this guide, we will walk through the most practical techniques to fix critical errors on WordPress, restore your site’s functionality, and reduce the likelihood of encountering similar mistakes down the line.

What Causes a Critical Error on WordPress?

A critical error on WordPress typically emerges from server-side or coding-level conflicts. Here are the most frequent triggers:

Plugin Conflicts

Two or more plugins may clash if they rely on the same hooks or incompatible PHP libraries. A plugin update or installation can also introduce conflicts.

Theme Malfunctions

Themes sometimes rely on code snippets that don’t align with the WordPress core or your existing plugins. This can generate errors that bring the site down.

Corrupted Core Files

Failed updates or incomplete file transfers can damage critical WordPress files, stopping the CMS from loading necessary scripts.

Insufficient PHP Memory

Every script requires memory to run. If your site exceeds its designated limit, you may see a critical error on WordPress indicating a memory shortage.

Malicious Code

Sometimes, hackers or malware can inject scripts that break your site’s normal flow. This scenario may also produce odd behaviours or lock users out entirely.

Step 1: Look for the WordPress Recovery Email

WordPress has a built-in safety mechanism that tries to pinpoint the source of the critical error on WordPress and emails you details on it. The subject line typically reads, “Your Site is Experiencing a Technical Issue,” the body may specify the plugin or theme that triggered the error.

• Check Spam/Junk: If you don’t see it in your inbox, look in your spam folder.
• Follow Recovery Link: The email often includes a link to Recovery Mode. Clicking it gives you partial WordPress admin access to remove or deactivate problematic plugins or themes.

If you can’t find the email, there is no need to worry—manual steps can still solve the error.

Step 2: Enable Debugging for More Clarity

When email insights aren’t available, switching on WordPress Debug Mode is the quickest way to learn the root cause of the critical error on WordPress.

1. Access wp-config.php

Use FTP or your hosting’s File Manager to locate wp-config.php in the main WordPress directory.

2. Edit Debug Constants

Inside the wp-config.php, just before the line /* That’s all, stop editing! Happy publishing. */, add or modify the following:

 3. Review the Log

After saving, reload your website. Errors should be recorded in a debug.log file inside wp-content. Check that file for lines pointing to the plugin, theme function, or core file that triggered the critical error on WordPress.

Remember to revert these changes (by setting them to false) once the issue is resolved. Leaving debug mode active on a live website can expose sensitive information.

Step 3: Deactivate Plugins

Because plugins are a common source of conflicts, turning them all off at once can clarify whether they are behind your critical error on WordPress.

1. Via Admin Dashboard (if accessible)

Go to Plugins → Installed Plugins, tick the checkbox to select them all, and choose Deactivate.

2. Via FTP (if admin is inaccessible)

• Connect to your server through an FTP client.
• Navigate to wp-content/plugins.
• Rename the plugins folder to something like plugins-deactivated.

If your site then loads without a critical error on WordPress, you know a plugin is at fault. Begin reactivating them one by one to detect which plugin triggers the error. When you find the culprit, seek updates, contact its developer, or look for a more reliable alternative.

Step 4: Switch to a Default Theme

If disabling plugins doesn’t solve the issue, examine your theme next. Themes can also create critical errors on WordPress if they conflict with updates or rely on flawed code.

1. Via Dashboard

Go to Appearance → Themes and activate a default theme, such as Twenty Twenty-Three.

2. Via FTP

Rename your active theme’s folder in wp-content/themes. For instance, mytheme becomes mytheme-old. WordPress will revert automatically to a default theme if one is available.

Refreshing your site afterward helps confirm if the old theme caused the critical error on WordPress. Should that be the case, reinstall a fresh copy or use a more stable theme.

Step 5: Increase Your PHP Memory Limit

When memory usage hits its cap, scripts cannot run correctly, triggering a critical error on WordPress. To boost the limit:

1. Locate wp-config.php and add:

This sets the memory to 256 MB, which is often enough.

2. Check with Your Host

Some hosting plans don’t allow custom memory overrides. Confirm with your provider that you are permitted to raise your PHP limit if the error still appears.

Step 6: Reinstall Key WordPress Files

Another method to fix a critical error on WordPress is to restore or reinstall your core files, especially if a partial update damages them.

1. Download WordPress Core

Grab the latest version from the Official WordPress Website.

2. Overwrite Folders

In your FTP client, upload the wp-admin and wp-includes folders to your existing WordPress install, overwriting the old ones. Avoid replacing wp-content, which holds your themes, plugins, and media.

3. Preserve wp-config.php

Don’t overwrite your wp-config.php file. It contains crucial database login details.

After these steps, load your site. This often solves deeper corruption issues that cause the critical error on WordPress.

Step 7: Scan for Malware or Suspicious Code

If none of the above solutions work or if you suspect a security breach caused the critical error on WordPress, run a malware scan. Look for unusual scripts and code inserted in your files:

1. Use a Security Plugin

Tools like Wordfence or Sucuri can perform thorough scans and remove malware.

2. Hosting Provider Check

Some web hosts offer free malware scanning. Contact them for assistance if you are locked out or suspect malicious activity.

Keeping your plugins, themes, and WordPress core updated reduces the chance of malicious intrusions.

Final Thoughts

A critical error on WordPress can happen for many reasons: plugin conflicts, theme incompatibility, memory limits, and more. While the error message can appear intimidating, there is usually a straightforward fix. By systematically disabling plugins, switching themes, raising PHP memory, or reinstalling core files, you can often restore your site’s functionality in no time.

WordPress remains a powerful and flexible CMS, but it does need regular upkeep to minimise glitches and security concerns. If you are looking for reliable support or high-performance infrastructure, Crazy Domains has you covered. With 24/7 support and scalable hosting solutions, we are ready to help you keep your site online and thriving.

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