Spotify has removed Local Files

[conraddent]

I had about 2000 or so local files, which up until last week were showing and playing fine on Spotify. 

Now when I go to the local files option, it doesn't display anything. Not even greyed out songs. 

I can't find these local files on my computer, but they have always been able to be played through Spotify. 

They have just vanished tho, any ideas?