How to fix PHP Fatal error: Cannot declare class WP_Metadata_Lazyloader?

PHP Fatal error: Cannot declare class WP_Metadata_Lazyloader, because the name is already in use in /opt/bitnami/wordpress/wp-includes/class-wp-metadata-lazyloader.php on line 32

The error message you’re seeing indicates that the class WP_Metadata_Lazyloader is being declared more than once in your WordPress setup. This can happen due to a variety of reasons, such as:

1. Plugin Conflicts: Two or more plugins might be trying to declare the same class.
2. Theme Conflicts: The active theme might be declaring a class that’s already declared by WordPress core or a plugin.
3. Corrupted Core Files: Sometimes, core WordPress files can get corrupted during updates or due to other reasons.
4. Manual Code Additions: If someone manually added code to the functions.php file or any other file, it might be causing the conflict.

Here’s how you can troubleshoot and potentially fix the issue:

1. Deactivate All Plugins: Start by deactivating all plugins. If the error goes away, it’s likely a plugin causing the issue. Reactivate plugins one by one until you find the culprit.
2. Switch to a Default Theme: Switch to a default WordPress theme like Twenty Twenty-One. If the error disappears, the issue might be with your theme.
3. Check for Manual Code Additions: Look into the functions.php file of your theme and any other custom code areas to see if the class WP_Metadata_Lazyloader is being declared.
4. Re-upload Core Files: If none of the above steps work, consider re-uploading the WordPress core files. Download a fresh copy of WordPress from the official website and replace the wp-includes and wp-admin directories. Make sure to backup your site before doing this.
5. Check Server Logs: Your hosting might have logs that provide more details about the error. These logs can give clues about which file or plugin is causing the conflict.
6. Seek Expert Help: If you’re unable to resolve the issue, consider reaching out to a WordPress expert or developer for assistance.

Remember to always backup your website before making any changes. This ensures that you can quickly restore your site to its previous state if something goes wrong.