Duplicate items in Lightbox
When hyperlinking any of the Item Skin’s “parts” (Media, Cover or Layers), it’s important to keep in mind that applying a hyperlink to more than one “part” will cause the content to be loaded twice or more inside the lightbox (you’ll see duplicates of the same item). This is because all lightbox hyperlinks are considered separate lightbox items.
It could be that in the Skin Editor you have linked the lightbox for example to the item cover and a lightbox icon. These two will force one image to appear twice in the lightbox set.
To resolve that just remove one of two (or more) links by setting the link to “none”.
Click on the images to enlarge.