How come I cant add music to windows movie maker?

Everytime I try to add music to windows movie maker this happens:
C:UsersmDownloadsChris Brown - F.A.M.E Deluxe 2011-MP3-CovBubanee5 -
She Ain't You.mp3 could not be imported. The selected file is not
valid or is corrupted.

I dont know what to do. Its under .mp3