[Fancy Gallery Pro] gallery thumbnails not showing

I previously used Fancy Gallery Lite version and everything worked like a charm. Today I switched to Fancy Gallery Pro version by Dennis Hoppe and none of my gallery thumbnails aren′t showing up.

I know they′re there because when I turn the plug-in off WordPress is capable of showing them. Here′s the site: https://www.middlegrays.com

So what is happening with those thumbnails? Could anyone help with this problem? I have also tried to make a totally new gallery after the swith but it suffers from the same problem…

I′d be grateful for all the help with this one!