WordPress Site Editor Not Loading or Missing

Quick fix: check Appearance in the admin menu. If you see Customize and Widgets instead of Editor, the active theme is a classic theme and the Site Editor does not apply. If Editor is there but never finishes loading, the cause is the REST API or JavaScript — both are covered below.

Symptom 1: no Editor menu item

The Site Editor is only available with a block theme active. Switch to one — Twenty Twenty-Four, Twenty Twenty-Five or another block theme — under Appearance → Themes.

Two things to know before switching:

• Widgets and classic menus do not carry over. Navigation moves into the Navigation block, and widget areas become template parts.
• Customizer settings from the old theme do not transfer either.

If you want the model explained first, read what is a WordPress block theme. If you plan to switch a live site, follow how to change a WordPress theme so the change is staged rather than improvised.

A hybrid theme can add block template parts while remaining classic. In that case some editor features appear and others do not, which is expected rather than broken.

Symptom 2: endless spinner

The editor loads its shell and then hangs. This is nearly always the REST API.

Test the endpoint directly by opening https://example.com/wp-json/wp/v2/types while logged in. You should get JSON. If you get a 401, 403, 404 or an HTML error page, that is the failure.

Common blockers:

• Security plugins with an option to disable the REST API for logged-out or all users.
• Server rules blocking /wp-json/ or requiring authentication headers that get stripped.
• A missing Authorization header — some servers drop it, which breaks authenticated REST requests. The .htaccess line RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}] exists to prevent this.
• Permalink problems, since /wp-json/ is a rewrite. Test ?rest_route=/wp/v2/types; if that works and /wp-json/ does not, fix permalinks first.

The Site Health screen at Tools → Site Health reports REST API failures explicitly, and it is worth checking before anything else.

Symptom 3: blank white editor screen

The page loads, the admin menu renders, and the editing area stays empty. That is a JavaScript failure.

Open the console and read the first error, not the last. Typical causes:

1. A plugin enqueueing a conflicting script in the editor. Test by disabling plugins in batches.
2. Aggressive optimisation — deferring or combining admin JavaScript breaks the editor. Exclude admin pages from optimisation entirely.
3. An outdated block plugin compiled against an older version of the editor packages.
4. Browser extensions, particularly ad blockers and privacy tools. Test in a private window with extensions off.

Symptom 4: templates load but will not save

Saving writes to the database as wp_template and wp_template_part posts. Failures here usually mean permissions or a request that never completes:

• the user's role lacks edit_theme_options;
• a security rule blocks POST requests to the REST API;
• a proxy or firewall times out on the larger save request;
• the database user cannot write, which would also break normal post saving.

Check whether editing a normal post saves correctly. If that fails too, the problem is site-wide rather than editor-specific.

Symptom 5: the editor shows stale content

Block templates are cached in several places at once: the browser, an object cache, a page cache and sometimes a CDN. After a theme update, the editor can keep showing the old template.

Purge in order — object cache, page cache, CDN, browser — then reload. If your theme ships template changes and the editor still shows the old version, check Appearance → Editor → Templates for a customised copy: a template you edited earlier takes precedence over the theme's file until you clear the customisations.

The general ordering is described in WordPress changes not showing.

Recover access when nothing loads

If you cannot use the editor at all and the site is broken, edit templates from the filesystem. Block templates are plain HTML in the theme's templates/ and parts/ directories, and a child theme can override any of them.

To rule out theme corruption entirely, rename the theme folder over SFTP; WordPress falls back to a default theme and the admin becomes usable again — the same technique as disabling plugins without admin access.