Can’t add albums to Gallery

This is an error I am getting.

Uncaught TypeError: $childs.unshift is not a function
toggleItem https://ffshp.be/wp-content/plugins/tm-photo-gallery/media/js/admin/gallery/editor/components/grid.js:164
onClickItem https://ffshp.be/wp-content/plugins/tm-photo-gallery/media/js/admin/gallery/editor/components/grid.js:146
jQuery 8
initEvents https://ffshp.be/wp-content/plugins/tm-photo-gallery/media/js/admin/gallery/editor/editor.js:308
init https://ffshp.be/wp-content/plugins/tm-photo-gallery/media/js/admin/gallery/list/components/content.js:127
<anonymous> https://ffshp.be/wp-content/plugins/tm-photo-gallery/media/js/admin/constructor.js:16
jQuery 10
grid.js:164:15