Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
Spotify Allows Developers To Take Advantage Of Service –
Spotifys new announcement was that it is going to be opening up there massive music library to developers. The aim of this is to allow Spotify to become a base and allow developers to expand the offering and to create visually and functionally amazing HTML 5 applications.Spotify hopes to launch with around 30 applications. The 30 applications include apps made by by BillBoard, Rolling Stone and Last.fm. When you first install and app you will see it in your sidebar. To find new apps you can use the App finder which is a very similar style to the iTunes experience. Do not go searching for this feature on your mobile device because it is not available yet but is expected in the near future.