Drag and Drop Playlists Not Working

[treater]

Ever scince I have downloaded spotify onto my PC, I have been able to drag and drop playlists into a playlist folder no problem. But just until recently, I have been unable to do so. I have deleted the playlist folder and created a new one. I have logged out and logged back in again. I have even uninstalled and reinstalled spotify, but the broblem continues. Any one else having this problem and/or knows a solution? Thanks.