Introduction

When WordPress shows Updating failed or Publishing failed, the editor usually is not the real source of the problem. The block editor depends on the REST API being reachable from the same site URL, protocol, and authentication context as the page you are using. If that request breaks, saving content fails even though the dashboard itself still loads.

Symptoms

  • The post editor shows Updating failed or Publishing failed
  • Changes do not save even though the admin page remains open
  • The REST API works sometimes but fails on edit actions
  • The issue started after enabling HTTPS, changing domains, or adding security rules
  • Browser developer tools show blocked API calls, redirects, or unexpected error responses

Common Causes

  • The WordPress REST API is blocked, redirected, or returning errors
  • Site URL, home URL, or HTTPS settings do not match the actual admin hostname
  • Security plugins, WAF rules, or basic auth interfere with authenticated REST requests
  • Permalink or rewrite problems break API routes
  • Proxy or CDN settings change headers, cookies, or origin behavior needed for editor requests

Step-by-Step Fix

  1. Open browser developer tools and inspect the exact REST API request that fails during publish or update.
  2. Check whether the failing request returns a redirect, authentication error, blocked status, timeout, or server-side fatal error.
  3. Verify that WordPress home URL, site URL, admin URL, and HTTPS behavior all point to the same canonical hostname.
  4. Test the REST API directly from the same environment and login context to confirm it is reachable without redirect loops or mixed-host issues.
  5. Review security plugins, WAF settings, proxy rules, and basic auth layers that may allow page loads but block editor API requests.
  6. Refresh permalink rules and confirm API rewrite paths still resolve correctly after domain or server changes.
  7. Inspect server and PHP logs for hidden fatal errors in plugins or themes that trigger only during save requests.
  8. Retest the editor after each targeted fix by editing the same draft so you can confirm the publishing path is stable again.
  9. Keep canonical URL and proxy ownership documented because mismatched host and HTTPS settings are a common way to break the editor later.