[Steven Zahm]

@ Rebekah

Well… I’ve narrowed down the issue. It is being caused by the theme. When the Customizer is loaded it enqueues this script:

/themify/customizer/js/themify.customize-control.js

In this script, after the pages loads it does this:

$('#accordion-section-themify_options').find('.accordion-section-title').trigger('click');

What this does is force their Customize Panel to be active but since it is not available all you get is the blank Customizer. In my opinion this is very aggressive and should not be done because it is bound to break other plugins that rely on the Customizer too.

What I was able to do was add a bit of code which de-enqueues this script when customizing a template. Now it works as it should. Enjoy!