How can I resolve a WordPress 503 error caused by a plugin conflict?

To resolve a 503 error due to a plugin conflict, you'll need to disable all plugins. Access your WordPress files via FTP or your hosting control panel's file manager, navigate to the `wp-content` directory, and rename the `plugins` folder to something else (e.g., `plugins_old`). This will deactivate all plugins. If the error resolves, you can then rename the folder back and reactivate plugins one by one to identify the culprit.