Songs disappearing from playlist despite still being on Spotify databse

[timsandler]

Today I was listening to Happy Cycling by Boards of Canada and tried to come back to the song later to play it but it had been removed completely from all my playlists, despite having only listened to it a few hours previously and not tampered with the song myself. 

I know this isn't an issue about the song being removed from Spotify's system altogether as it wouldnt be removed and then reappear from Spotify in the space of a few hours and the rest of the album that the song came from still remained intact on the playlists.

Does anyone know why or how this happened and how I can stop it from happening in the future?

[MattSuda]

Hey @timsandler

To make sure songs do not get removed from your playlist when they become unavailable you can go into settings and turn on the option to show unavailable songs in playlists.