Thx – I just discovered how to do it:
Within: “\ml-slider\inc\metaslider.imagehelper.class.php
Line 27:
Change from: $this->url = $upload_dir['baseurl'] . "/" . get_post_meta($slide_id, '_wp_attached_file', true);
To: $this->url = get_post_meta($slide_id, '_wp_attached_file', true);
This changed the HTML output and thus now allows to pull from the CDN. 🙂
However the error still shows in the admin and to fix that, remove lines 269 thru 281
