We will be happy to look into this for you. Could you provide a link to the page where the problem occurs? We can then see what sort of error is being generated and perhaps tell where to go from there. Thanks in advance.
We were able to do some testing on your site. It appears that there are JavaScript errors on the page that are preventing fancybox, the slideshow script included with RPS Image Gallery, from operating properly.
Once the script theme.main.min.js, included with the theme your site is using, is removed from the head of the page, RPS Image Gallery works properly. The two remaining errors are generated by assets included with another plugin and do not have an adverse effect.
We recommend contacting the theme developer for a resolution to this issue. Let us know if you have additional questions.
We have looked into this issue further and there may be something we can do to alleviate the problem. We will be in touch soon.
As it turns out, in addition to the modifications we made in version 1.2.20, we should have updated the way the jQuery library was being called. That particular issue has been corrected in version 1.2.21 and should correct the problem based on our testing of the sample page you provided. Please let us know if further action is necessary and how the updated version works for you.