Enabling Post Thumbnail for CPT

Hi there,

I’m using WP GeoDirectory on a custom theme I’m developing. I set up the default custom post type gd_place and now I’m trying to enable the post thumbnails.

I did the following:

1. checked the Thumbnail option in Advanced Mode > Supports in the Edit panel of the CPT
2. added support for post-thumbnails in my theme as follow:

add_theme_support( 'post-thumbnails', array( 'post', 'page', 'gd_place' ) );

But the default Post Thumbnail box still doesn’t show up in the backend of WordPress (see attachments).

What am I missing?

Thanks,

Simone