❗ “Your site doesn’t include support for the '*' block.” — What It Means & How to Fix It - Woracious

If you’ve seen this message in the WordPress Site Editor:

“Your site doesn’t include support for the ‘namespace/block-name’ block. You can leave it as-is or remove it.”

…you’re probably scratching your head wondering what went wrong — especially if you just registered a custom block and added it to a template.

This guide walks through why this error happens, how to fix it using current block development best practices, and how to future-proof your custom blocks using block.json.

🔍 What the Error Means

This message appears when the block editor encounters a block it can’t find — often because WordPress doesn’t know how to render or load the block on the backend.

This usually happens when:

A custom block is referenced in a block-based template (like index.html) but hasn’t been properly registered.
The block’s JavaScript or PHP logic isn’t loaded in time (or at all).
The block is missing or incorrectly declared in your theme or plugin.
You’re using outdated or partial block registration code.

📦 Example Scenario

You create a block and add it to a template like this:

<!-- wp:mytheme/project-navigation /-->

But when you load the Site Editor or preview the page, you get:

“Your site doesn’t include support for the ‘mytheme/project-navigation’ block.”

This means WordPress doesn’t recognize the block name mytheme/project-navigation — either because it wasn’t registered, or it was registered too late.

✅ The Modern Fix: Use `block.json`

To ensure your custom block is fully supported, use block.json — the current standard for registering blocks in WordPress.

Why `block.json`?

Registers the block with metadata
Loads scripts, styles, and render files
Makes blocks discoverable by the Site Editor
Works cleanly with block themes and FSE

🧱 Example Block Setup

Let’s create a block that adds Previous/Next navigation to custom post types like Projects.

📁 Folder structure:

/theme
  /blocks
    /project-navigation
      block.json
      index.js
      render.php

1. `block.json`

{
  "apiVersion": 3,
  "name": "mytheme/project-navigation",
  "title": "Project Navigation",
  "category": "widgets",
  "icon": "leftright",
  "description": "Adds Previous and Next links to single Project posts.",
  "editorScript": "file:./index.js",
  "render": "file:./render.php"
}

2. `index.js`

import { __ } from '@wordpress/i18n';
import { useBlockProps } from '@wordpress/block-editor';
import { registerBlockType } from '@wordpress/blocks';

function EditProjectNavigation() {
  const props = useBlockProps();
  return (
    <div {...props}>
      <p>{__('This block will show previous and next project links on the front end.', 'mytheme')}</p>
    </div>
  );
}

registerBlockType('mytheme/project-navigation', {
  edit: EditProjectNavigation,
  save: () => null // Rendered server-side
});

💡 Define components before calling registerBlockType() to avoid ReferenceError due to JavaScript hoisting rules.

3. `render.php`

<?php
function render_project_navigation_block( $attributes, $content ) {
    if ( ! is_singular( 'project' ) ) {
        return '';
    }

    $prev = get_previous_post_link( '%link', '← Previous Project', true );
    $next = get_next_post_link( '%link', 'Next Project →', true );

    return sprintf(
        '<nav class="project-nav">%s %s</nav>',
        $prev ?: '<span class="no-link">No previous</span>',
        $next ?: '<span class="no-link">No next</span>'
    );
}

You can use any logic here — this example only renders on project post types.

4. `functions.php` (or your plugin file)

add_action( 'init', function() {
    register_block_type( __DIR__ . '/blocks/project-navigation' );
});

No need to manually enqueue JS or register render callbacks — WordPress reads everything from block.json.

🧪 Troubleshooting That Error

✅ Checklist	Details
Block name matches?	The name in your template (e.g. `<!-- wp:mytheme/project-navigation /-->`) must match `block.json`.
JS/Render files exist?	Are `index.js` and `render.php` actually present and error-free?
Scripts loaded early enough?	Don’t delay block registration with late hooks.
Any typos in `block.json`?	Even small issues can prevent the block from registering.
Site Editor reloaded?	Sometimes a browser hard refresh is needed to pick up new blocks.

✅ Summary

If you see:

“Your site doesn’t include support for the ‘*’ block.”

…it means the block editor can’t recognize your block.

To fix it:

Use block.json to register your block cleanly
Make sure all assets (JS, PHP, styles) are declared and loaded
Match the block name exactly in your templates
Avoid hoisting issues in JS (const vs function)

📚 Helpful Links

Let me know if you’d like a working example or have a specific error trace — happy to help debug!

❗ “Your site doesn’t include support for the ‘*’ block.” — What It Means & How to Fix It

🔍 What the Error Means

📦 Example Scenario

✅ The Modern Fix: Use block.json

Why block.json?