We previously introduced new playlist representations. The compact representation returns only the playlist itself without any of the tracks. For most users, this is preferable – the compact representation significantly reduces the size of the JSON payload for large playlists and provides faster API response times.
Beginning July 15, 2016, all queries using the q parameter will only return this compact representation for playlists. Other playlist representations will no longer be available when using the q parameter.
To fetch the track listings for one of the returned playlists, you can make an additional request to the /playlists/{id} resource by using the corresponding playlist ID.
If your application expects track listings from playlist search results, update your application by July 15, 2016.