One gallery, 2 popups!

This is a development site using theme Bootstrap Ultimate.

I have inserted a gallery here: http://www.disana.co.uk/?p=114 and I get another gallery popup underneath yours, so when I close yours there is another still there !

Any ideas?

ps I dont have any other gallery plugin or standard WP gallery item on this page

https://wordpress.org/plugins/wp-bootstrap-gallery/