Why can't I play mp3 ringtones any longer?

[AC Question]

I have Galaxy S3 with Andriod 4.4.4 and suddenly all my notifications and ringtones have gone back to default and I can only play default listings. Going through menu to change tones I can find the mp3 Zedge downloads that used to play but when I get back to the main menu the it shows 'unknown ring tone'. It doesn't seem to want to play MP3 tones any longer.

 

[B. Diddy]

Welcome to Android Central! Are you custom ringtones on your microSD card? Make sure they're in the Ringtones directory on Internal Storage.