"Equip" Button fails to load for custom skinpacks

I just noticed this issue as I don't really change skins all too often. I use a custom made skinpack as it makes it much easier to manage and switch skins without having to open an external window all the time. However, in recent updates, the skin selector will only display "Loading" with a spinning circle, never advancing to the Equip button. Please fix, as this ruins one of the better ease of use features of classic skins.