This was posted previously but I can't reply because it was closed.
I'm having the same issue on my site:
I've tried to follow the instructions but I'm new to this and when I removed the masonry instructions in the editor the slider stopped working. I believe this is because need to edit the custom.js file, and although I've been able to find it I have no idea how to edit it! Or upload a new one or whatever I need to do.
Some help would really be appreciated as I've spent hours trying to fix this problem.