The 500 Internal Server Error is one of the most frustrating errors you can encounter. Unlike specific error codes, a 500 error is a generic message that indicates something went wrong on the server, but doesn't tell you exactly what.

What is a 500 Internal Server Error?

A 500 error is an HTTP status code that means the server encountered an unexpected condition that prevented it from fulfilling the request. It's a server-side error, meaning the problem is with the website's server, not your browser or internet connection.

Common Causes of 500 Errors

1. PHP Errors or Syntax Mistakes

A typo or syntax error in your PHP code can trigger a 500 error. This is especially common after updating plugins, themes, or custom code.

2. .htaccess File Issues

The .htaccess file controls important server settings. A corrupted or incorrectly configured .htaccess file is a frequent culprit.

3. PHP Memory Limit

If your website runs out of allocated PHP memory, it can result in a 500 error. This often happens with resource-intensive plugins or themes.

4. Plugin or Theme Conflicts

Incompatible WordPress plugins or themes can cause server errors, especially after updates.

5. Server Timeout

If a script takes too long to execute, the server may timeout and return a 500 error.

How to Fix a 500 Internal Server Error

Step 1: Check Server Error Logs

Your server's error log contains detailed information about what caused the error. Look for entries at the time the error occurred.

/var/log/apache2/error.log
/var/log/nginx/error.log

Step 2: Test Your .htaccess File

Rename your .htaccess file temporarily to see if it's causing the issue:

mv .htaccess .htaccess_backup

If your site works, regenerate a fresh .htaccess file from your WordPress settings.

Step 3: Increase PHP Memory Limit

Add this line to your wp-config.php file:

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

Step 4: Deactivate All Plugins

If you can access your admin panel, deactivate all plugins and reactivate them one by one to identify the culprit. If you can't access the admin, rename the plugins folder via FTP.

Step 5: Switch to Default Theme

Temporarily switch to a default WordPress theme to rule out theme-related issues.

Step 6: Check File Permissions

Incorrect file permissions can cause 500 errors. Standard permissions should be:

  • Folders: 755
  • Files: 644

Preventing Future 500 Errors

  • Keep WordPress, plugins, and themes updated
  • Test updates on a staging site first
  • Monitor server resources and upgrade when needed
  • Use quality hosting with proper PHP configuration
  • Implement regular backups

Conclusion

While 500 errors can be frustrating, they're usually fixable with systematic troubleshooting. Start with the most common causes and work your way through until you identify the issue.

Tired of dealing with server errors? ZenoCloud's managed hosting includes proactive monitoring and expert support to prevent and quickly resolve issues.