How to Fix PHP Error 500: Internal Server Error in WordPress ?

Error 500, also known as “Internal Server Error,” is a common issue in PHP and WordPress sites. It’s a generic error indicating that something has gone wrong on the server, but the server is unable to specify the exact problem. Here’s how to troubleshoot and fix the 500 Internal Server Error in WordPress:

Steps to Solve 500 Internal Server Error in WordPress

1. Enable Debugging in WordPress

• To get more information about what’s causing the error, you can enable WordPress debugging.
• Edit the wp-config.php file, located in the root directory of your WordPress installation.
• Find the line that says:
  

Change it to:

This will create a debug.log file in the wp-content folder, which will log any errors. Check the file for clues to the source of the issue.

2. Check for Corrupt .htaccess File

The .htaccess file could be corrupted, which often leads to a 500 error.

To check this, follow these steps:

1. Connect to your website using FTP or the file manager in your hosting control panel.
2. Look for the .htaccess file in the root directory where WordPress is installed.
3. Rename the file to something like .htaccess_old.
4. Reload your website. If the site works, the problem is with your .htaccess file.

To regenerate a new .htaccess file:

1. Go to your WordPress dashboard.
2. Navigate to Settings > Permalinks and click “Save Changes.” This will automatically generate a fresh .htaccess file with default settings.
   
   

3. Increase PHP Memory Limit

Sometimes, a low memory limit can cause a 500 error.

To increase the PHP memory limit:

1. Edit the wp-config.php file.
2. Add the following line just before the line /* That's all, stop editing! Happy blogging. */:
   
   

define(‘WP_MEMORY_LIMIT’, ‘256M’);

Alternatively, you can create or edit a php.ini file in your root directory and add:

memory_limit = 256M

Or, if using .htaccess, you can add:

php_value memory_limit 256M

4. Deactivate All Plugins

Faulty or incompatible plugins are a common cause of 500 Internal Server Errors in WordPress.

To identify if a plugin is the cause, deactivate all plugins:

1. Access your site’s files via FTP or your hosting file manager.
2. Navigate to the wp-content directory and rename the plugins folder to something like plugins_old. This will deactivate all plugins.
3. Reload your site. If it works, the issue lies with one of the plugins.

To find the faulty plugin:

Rename the folder back to plugins.

Reactivate plugins one by one via the WordPress dashboard, reloading your site each time to check for the error.

5. Revert to Default Theme

• Sometimes, the theme may be causing the error. To test this, switch to a default WordPress theme like Twenty Twenty-One:

Log in to your WordPress admin panel and go to Appearance > Themes.

Activate one of the default WordPress themes.

• If you can’t access the admin area, use FTP to manually deactivate your theme:

Go to the wp-content/themes directory and rename your current theme’s folder.

WordPress will then automatically fall back to a default theme.

If the error is resolved, it means the problem was with your theme.

6. Check File and Folder Permissions

• Incorrect file permissions can also trigger a 500 Internal Server Error.
• Typically, the correct file and folder permissions for WordPress are:
  • Folders should be set to 755.
  • Files should be set to 644.
• To fix permissions:

Connect via FTP or your host’s file manager.

Ensure that your directories (folders) have permissions set to 755 and files are set to 644.

7. Check PHP Version Compatibility

• WordPress requires a certain version of PHP to function correctly. An outdated PHP version may cause issues.
• Ensure your site is running on at least PHP 7.4 (or newer if possible). Many hosts allow you to change the PHP version via the hosting control panel.
• Contact your hosting provider or refer to your control panel’s documentation to upgrade PHP.
  
  

8. Re-upload Core WordPress Files

• Sometimes, WordPress core files can become corrupted.
• To fix this:

Download a fresh copy of WordPress from wordpress.org.

Unzip the file and upload the wp-admin and wp-includes folders via FTP, replacing the existing ones on your server.

• Don’t worry, this won’t affect your content or settings.
  
  

9. Contact Your Hosting Provider

• If none of the above methods work, the issue may lie with the server configuration. Your hosting provider may have encountered a temporary problem, or there may be specific issues with your hosting environment.
• Contact your host’s support team, and they should be able to provide assistance or check for any server-related issues that could be causing the 500 error.