Media Library and Visual Editor not working

I’ve recently upgraded to 4.1 and haven’t composed a post for a while but now the visual composer has stopped working (displays blank box with no toolbar or content) and the media library doesn’t display either.

I get the following JS errors in the console:

Visual composer
http://www.#######.com/wp-includes/js/plupload/wp-plupload.min.js?ver=4.1 Failed to load resource: the server responded with a status of 522 (Origin Connection Time-out)

Also
Failed to load: http://www.######.com/wp-includes/js/tinymce/plugins/wpeditimage/plugin.min.js

Media Library
http://www.#######.com/wp-includes/js/plupload/wp-plupload.min.js?ver=4.1 Failed to load resource: the server responded with a status of 522 (Origin Connection Time-out)

media-grid.min.js:1 Uncaught TypeError: Cannot read property ‘limitExceeded’ of undefined
media-views.min.js:1 Uncaught TypeError: Cannot read property ‘where’ of undefined
16wp-auth-check.min.js?ver=4.1:1 Uncaught TypeError: Cannot read property ‘hasClass’ of undefined

What I have tried
Reinstalling WP 4.1 from the zip file.
Disabling all plugins
Clearing the cache and using multiple browsers
Switching to a new theme (but I am using Two Thousand Eleven anyway)
Adding define(‘CONCATENATE_SCRIPTS’, false); to the wp-config.php file

I’m really at a loss now. Can anyone help?

Thanks