Cannot read property 'frames' of undefined

Your error is a Javascript error, nothing to do with the code you posted.

Try deactivating your plugins until the error goes away. It sounds like you are loading custom JS for your custom post type.

Hi there,
First of all i would like to say thanks for this excellent plugin, which indeed saved my several hours of development.

Regarding to above problem, it seems if a post type does not include editor, then media file support does not available that’s causing error. Although, this plug-in working fine if editor is enable for that post type.

To solve this i have added following code in easy-image-gallery/metabox.php

function my_load_wp_media_files() {
  wp_enqueue_media();
}
add_action( 'admin_enqueue_scripts', 'my_load_wp_media_files' );

That solved my problem, there must be better way to do this, just want to share with you guys

Thanks