Cant play songs from SD Card

[AC Question]

I just got my s7 last week and I'm having problems syncing and playing my iTunes Playlists to my phone. I have formatted my SanDisk 64gb micro SD card twice and factory reset my phone. My songs played fine on my s5, I don't understand why they are not playing on my s7. I use the Samsung stock music player, I don't like the Google play player. Some m4a and mp3 files will play and some will not. It says sorry the player does not support this audio file. Anyone else having this issue? Can anyone help me?