I reset my Galaxy Light (running Android 44.2) because when an incoming call arrived, the .m4a ring tone -- which had been playing perfectly for years -- cut off after no more than 1 second, followed by silence. I also rooted the phone for the first time before the reset so that I could install and run Titanium Backup Pro, which requires root. I did this so that I could restore everything after the reset (which didn't work fully, since some Google processes kept failing in an infinite loop). But the Google automatic restore seemed to work fine, except that none of my audio files (a mix of .m4a and Flac and mp3 files) would play at all! I downloaded and ran a little tool called Media Codec Info, which reported that all those codecs (and more) were present. So why whenever I try to play any audio file, whatever player I'm using reports an error to the effect that it "can't play that kind of file"? I've tried resettinng to the factory defaults again without trying a Titanium restore (just the automatic Google restore), but it still won't play any audio file (except for the pre-installed ring tones and notification sounds). What gives, and how can I fix this?