Undefined variable notice on upload

I adore this plugin, but though I would let you know that with debugging on I get the notice below every time I attach an image to a logo post.

Notice: Undefined variable: post_id in /Users/annfoley/Documents/plakes/wp-content/plugins/kiwi-logo-carousel/kiwi_logo_carousel_admin.php on line 207

Warning: Cannot modify header information - headers already sent by (output started at /Users/annfoley/Documents/plakes/wp-content/plugins/kiwi-logo-carousel/kiwi_logo_carousel_admin.php:207) in /Users/annfoley/Documents/plakes/wp-includes/pluggable.php on line 1195

Tried it with Twenty Fifteen, and also tried it after deactivating all my other plugins. I still got the notice.