'an unknown error has occurred.' well loading playlist.

Anytime I try to open my playlist, it says 'an unknown error has occurred.' I have tried signing out and in, deleting the app, creating a copy of the playlist, but nothing has fixed it. I've had this problem for about 2 weeks now. it also doesn't have that problem with the other playlist I have. it will still let me hit shuffle with right click and to all of those options, but I cannot access the playlist to edit it. any other thoughts or solutions I can try?