Not sure

Ive downloaded the app but as of yet, it will not accept any music from my library! I get a SORRY pop up box which says I cant use this song, pick another one! (no matter which one Ive picked, NONE have worked) also I dont see a way to email on the website! I need assistance please!!! Not above admitting operator error!

Monteleto about Ringtone Designer Pro 2.0, v1.9