Empty 'Embed Video' window in Black Studio TinyMCE Widget

Thanks for the splendid plugin!

I am seeing following a bug when embedding video to widgets.

I am using Black Studio TinyMCE Widget (aka Visual Editor) plugin. In Black Studio TinyMCE you have all the regular editor features, also the Embed Video button.

When I click the Embed Video button the embed window pops open but its empty. Only the heading line shows. The rest is blank. It seems that TB_ajaxContent container is empty.

I am still able to add the video through shortcodes, but having a functional Embed Video button would be great.

Thanks!

https://wordpress.org/plugins/advanced-responsive-video-embedder/