I've recently upgraded a site for the Add Media button wasn't working. Now, having upgraded to 4.2.2 the Add Media works, but the Wysiwyg editor isn't showing.

The only console messages I'm receiving are:

Uncaught ReferenceError: edButtons is not defined (anonymous function) @ post-new.php:131

The new post screen appears with the Text tab selected, instead of Visual, and when I try to select the Visual tab I get:

Uncaught TypeError: Cannot read property 'canvas' of undefined a.closeAllTags @ quicktags.min.js?ver=4.2.2:1 window.switchEditors.go @ editor.min.js?ver=4.2.2:1 window.switchEditors.switchto @ editor.min.js?ver=4.2.2:1 onclick @ post-new.php:405

Any ideas?

  • Have you cleared your browser cache? Jul 2, 2015 at 8:46
  • Yes. I've cleared caches.
    – Ikzer
    Jul 2, 2015 at 11:17

1 Answer 1


Check .htaccess file if it is blocking with this rule: #add_header Content-Security-Policy “default-src ‘self’;”;


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