Diagnosing a WordPress Admin Area You Cannot Access Print

If the public site or wp-admin fails after a plugin/theme change, use the least destructive path to regain access.

1. Check for a WordPress Recovery Mode email and use that path first when available.
2. Review debug/error logs for the component causing the fatal error.
3. If plugins are suspected and wp-admin cannot load, rename the wp-content/plugins directory through File Manager and visit /wp-admin/plugins.php while the folder remains renamed so WordPress records the plugins as deactivated. Then restore the directory name and reactivate plugins individually.
4. If the active theme is implicated, switch to a known-good theme when possible.
5. Do not reset the database or reinstall WordPress before identifying whether the failure is simply a plugin/theme fatal error.

Preserve a backup before making filesystem or database changes.

Documentation for this guidance: wordpress.org — faq troubleshooting.