Spotify Music Now Crypted , Can't Playing Offline

I am ripping with Internet Download Manager. Files is not .flv. , i'ts crypted mp3 files. I need the details or news.

Thanks.

Reply:
Recently I downloaded several albums with Spotify for use offline, inside the spotify code it does have this little bit of code that talks about how often music is played and if you don't touch a certain piece of music for 90 days, that piece of music automatically gets deleted. So why are you trying to use IDM?