This is the most common fix. You'll need access to your WordPress files via FTP or your hosting file manager.

1. Log in to your hosting control panel or connect via FTP
2. Navigate to your WordPress root folder (where WordPress is installed)
3. Find and open the file called wp-config.php
4. Look for this line:
   define( 'DISALLOW_UNFILTERED_HTML', true );
5. If you find it, change true to false:
   define( 'DISALLOW_UNFILTERED_HTML', false );
6. Save the file
7. Go back to your website and re-add the embed code

Solution 2: Check Security Plugins

Some security plugins block iframes. Check these common plugins:

• Wordfence — Go to Wordfence → All Options → search for "HTML" or "iframe"
• Sucuri — Check the hardening options
• iThemes Security — Look for content filtering settings
• All In One WP Security — Check firewall settings

Try temporarily disabling your security plugin, then re-add the embed code and publish. If it works, re-enable the plugin and look for a setting to allow iframes.

Solution 3: Contact Your Hosting Provider

Some hosting providers add security restrictions without telling customers. Contact your host and ask:

Hosts known to sometimes enable this restriction:

• IONOS
• Cloudron
• Some managed WordPress hosts