error message mp3

[siduramaxde]

I have sprint touch. I keep getting error message "The file 'filename' cannot be opened. Either it is not signed with a trusted certificate or one of its components cannot be found. If the problem persists, try reinstalling or restoring this file." This message only comes up when I try to play mp3 files from the File Explorer. The mp3's play fine from s2p or from the sprint music store player. I've tried reinstalling the mp3's but it didn't help. This problem started after I tried Nitrogen. I have since removed Nitrogen because it wasn't working correctly (probably user error). Thanks in advance for any help and please remember that I'm not too PPC savey.