Folders and ability to make folders vanished

[Schoota]

After toggling “Force VLC to Rescan Media Library” on in Settings because some video files copied via the Mac finder were not showing up in the library (and this was a widely recommended fix for that) all folders vanished and their contents remained in the video library. I attempted to reorganize the library. I selected a few files that should be together in a folder, but the icon (rectacular with a +) that usually appears in the lower right corner to put them in a Media Group no longer exists. What should I do to restore this important fuctionality?