Hey, Elloria. This has to be something easy
Make sure all of these are all correct:
1. File path. Make sure this is a seperate addon. (e.g. ButtonFacade_Undead)
2. Make sure you have the right name of the Skin.lua in both the TOC and the actual Lua file.
Hope this helps! (If it doesn't help, I can send you a template of a ButtonFacade skin I was playing around with that shows up. :P)