can't import mpg4 audio

I haven’t used audacity in a few years and downloaded the newest version. I tried to import an mpg4 song for conversion but I get an error message. Is there some way to fix this? I downloaded the song from Itunes. Do they have some kind of lock in the code or something so you can’t use it? I hope not! Who has the answrers?

FairPlay Copy Protection is one problem, yes, but the other is a lack of Audacity advanced coding without the FFMpeg add-on.