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How to Diagnose and Fix WordPress 500 Internal Server Errors

Last updated on Aug 08, 2025

How to Diagnose and Fix WordPress 500 Internal Server Errors

Description:
A comprehensive guide to help Brixly shared hosting customers identify and resolve common causes of WordPress 500 Internal Server Errors—including PHP configuration issues, file permissions, plugin conflicts, and more. This guide is tailored for users with basic technical knowledge and covers solutions you can implement directly from your hosting control panel.

Table of Contents

What is a 500 Internal Server Error?

A 500 Internal Server Error is a generic error message indicating that something has gone wrong on the server, but the server cannot be more specific about the exact problem. In WordPress, this error is often caused by issues with plugins/themes, PHP configuration, or file permissions.

Common Causes of 500 Errors in WordPress

  • Corrupt or misconfigured .htaccess file

  • PHP memory limits exceeded

  • Faulty or incompatible plugins

  • Theme errors

  • Incorrect file/folder permissions

  • Incompatible or outdated PHP version

  • Corrupted core WordPress files

Step-by-Step Troubleshooting Guide

1. Check for Corrupt .htaccess File

A misconfigured or corrupted .htaccess file is a common cause of 500 errors.

Steps:

  1. Log in to your cPanel.

  2. Open File Manager and navigate to your site's public_html directory.

  3. Locate the .htaccess file.
    If you can’t see it, enable “Show Hidden Files” in File Manager settings.

  4. Rename the file to .htaccess_backup.

  5. Try reloading your website.

  • If the site loads, your .htaccess was the issue.

  • To generate a new default .htaccess:

    • Log into your WordPress dashboard

    • Go to Settings > Permalinks and click Save Changes (no need to change settings)

2. Increase PHP Memory Limit

A low PHP memory limit can trigger 500 errors, especially on plugin-heavy sites.

Steps:

  1. In File Manager, locate and edit the wp-config.php file (in public_html).

  2. Add the following line just above /* That's all, stop editing! Happy blogging. */:

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

  3. Save the file and check your site.

If the error persists, your site may require a higher memory limit than your hosting plan allows. In that case, consider disabling resource-intensive plugins or upgrading your plan.

3. Deactivate All Plugins

A faulty plugin can easily cause a 500 error.

Via File Manager:

  1. Go to public_html/wp-content/.

  2. Rename the plugins folder to plugins_disabled.

    This will deactivate all plugins at once.

  3. Check your site.

    • If it loads, rename the folder back to plugins and reactivate plugins one-by-one from your WordPress dashboard to find the culprit.

4. Switch to a Default Theme

Themes can also trigger 500 errors if they’re corrupted or incompatible.

Steps:

  1. In public_html/wp-content/themes/, make sure a default theme (like twentytwentyfour) exists.

  2. If you can access the WordPress dashboard, go to Appearance > Themes and activate a default theme.

  3. If you can't access the dashboard, rename your active theme’s folder (e.g., mytheme to mytheme_backup).
    WordPress will automatically revert to a default theme if available.

5. Check File and Folder Permissions

Incorrect permissions can prevent WordPress from running properly.

Recommended permissions:

  • Folders: 755

  • Files: 644

To fix permissions via File Manager:

  1. Right-click the folder or file.

  2. Select Change Permissions.

  3. Set folders to 755 and files to 644.

Example:

public_html/wp-content/          755
public_html/wp-content/themes/   755
public_html/wp-content/plugins/  755
public_html/wp-config.php        644

Never set folders or files to 777. This is insecure and can be exploited.

6. Review PHP Version and Error Logs

Check PHP Version

Some plugins/themes require newer versions of PHP.

  1. In cPanel, go to Select PHP Version or MultiPHP Manager.

  2. Set your site to use a supported, recommended version (e.g., PHP 8.1 or newer).

  3. Save changes and test your site.

Check Error Logs

  1. In cPanel, open File Manager and look for an error_log file in public_html.

  2. Open it to review recent errors for clues.

You can also enable debugging in WordPress:

  1. Edit wp-config.php and add or change the following lines:

    define("WP_DEBUG", true);
define("WP_DEBUG_LOG", true);
define("WP_DEBUG_DISPLAY", false);

  2. Errors will be logged to wp-content/debug.log.

Advanced Troubleshooting

If the above steps do not resolve your issue:

  • Re-upload core WordPress files:
    Download a fresh copy of WordPress from wordpress.org. Upload all files except /wp-content/ and wp-config.php to public_html, overwriting existing files.

  • Restore from backup:
    Use JetBackup or cPanel’s Backup tool to restore your site to a point before the error occurred.

When to Contact Support

If you have tried all the steps above and are still experiencing 500 errors, please submit a support ticket with the following details:

  • Your domain name

  • Exact error messages or screenshots

  • What troubleshooting steps you have already taken

Our team can help investigate further and guide you through any advanced solutions.

Summary

WordPress 500 Internal Server Errors are usually fixable with the right approach. By systematically checking .htaccess, plugins, themes, PHP settings, and permissions, you can resolve most issues yourself using cPanel and File Manager. If you’re still having trouble, our support team is here to help.

Stay proactive: keep everything updated, use strong passwords, and make regular backups for a healthy website!