I logged out...back in...still the same perpetual "Loading..." of playlists but nothing more.
I have been having this problem for about a year. I have tried the following:
1. reset SmartHub
2. signed out of Spotify, signed back in
3. deleated Playlists on Spotify so that there isn't one in the 11th position (no Playlist or Folder)
4. updated Spotify and my Samsung Smart TV
Nothing is working... :(