Hello Vev,

Thank you for getting in touch with us. My name is Attila and I'm happy to assist you today. I appreciate your patience while we've been working towards your ticket.

The code you're looking for can be found at the bottom of the Glass skin in the Skin Editor:

.ls-glass .ls-shadow {
display: block;
}

The thumbnail shadows can also be found there, if you want to duplicate those as well.

Thank you for the feedback. My colleagues and I will look into this to see what might be wrong, and get back to you shortly.

Hello,

In case you want outline skin, you will need this code:

.ls-outline .ls-shadow {    
    display: block;
}

Or you can rename it to any other name depending on the skin. 

Furthermore, you will need to copy the shadow.png file from the glass skin's folder, to the outline skin folder.

It's also important to note that plugin updates will overwrite the default skins. So it's recommended to create new custom skin, and load it from external source as it's described here: https://support.kreaturamedia.com/docs/layersliderwp/developers.html#sources-skins