It looks like Spotify's new Windows 10 Store version is so popular it broke the Windows Store! The above error, together with the code 0x0000FFFF relates to an inability to connect to the Store's servers.
Seems to be too much of a coincidence that this happened almost immediately after Spotify's download link went live. The Centennial version of the desktop app has clearly proved to be popular with Windows 10 users, to the point where Microsoft's servers seem to have choked on demand.
Spotify recently announced it had hit 140 million users and we know there are half a billion users on Windows 10, clearly there's a large overlap in those two numbers and the resulting download storm may take a while to clear.