Lens Gallery's don't show any photo's anymore in wp-dashboard

Sinds today, after 7 years of using the theme Lens without issues, I uploaded a picture to an existing Gallery. From now on the Gallery’s don’t show any pictures anymore in the dashboard, in edit-mode. The site works okay though, but I can’t edit or add any Gallery at all. E.g.: https://www.roycoumansphotography.com/gallery/eveline/ The site looks ok, but the Dashboard is the problem. Any knows issues with this theme?


Contact with your purchase item author hope they will helped!