Hopefully there is a quick fix for this. I have a gallery with a lightbox installed and when you close the enlarged image of the lightbox it opens up a new tab with a blank page instead of just closing and being in the page where the gallery is. I have asked the developer of the gallery and they said it is probably due to the theme I'm using (first time I've used a third party theme). I have contacted the theme developer but haven't had a response yet. I have used the gallery before with my own theme and it's been fine. Could someone point me in the right direction as to what needs to be changed in what file?

Thanks.