Hello @loulla.stella and @gentlemood
Can you provide us some additional information about this issue? We need to know:
1. Link to your website, where we can see that problem.
2. The actual version of Free and Pro (if you have that one) Supsystic Gallery on your website.
3. What exact popup theme do you use for your gallery. I mean this information: http://prntscr.com/jje89x