Images and thumbnails are not showing

After switching hosting and updating Word Press, images in all ImageStore galleries stopped loading/showing. They are still loading on my side (when I logged in to my WP dashboard I can view all the galleries) but not on the clien’t side, when they access galleries from the front end.

My website runs on the basic default WordPress theme twenty fifteen and I have only a few plugins installed on this site that I tried disabling but this did not seem to help.

I have no idea what the problem is and how to fix it. I would love your help on this please since I love your product and would love to find a way to make it work again.

Website: http://applepixpro.com/proofs/galleries/test/
Password: 1

Thank you so much!