So my iTunes is refusing to let me add some music/audio files for a language I'm learning. It's giving me random errors. Like it'll say it can't sync one time, the next it asks me to restore. Or it won't say anything and just sync my phone. Any solutions to this problem? I haven't added music to this phone/device in about a year. I usually use my old 4s phone and it doesn't give me problems on there.