Nero MP3 codec wht does it do?

Ok guys firstly wht does this exactly do? i have nero 5.5.8.2 and when installed it creates an extra menu but gives an error.

invalid mp3pro plugin? is this a version clash if not tell me where can i get the codec for the above ver?

thanx!

You probably downloaded a cracked version, and Nero now won’t accept it.
Won’t work at all.