I have an Iphone 6s and when I try to transfer my MP3 music files from PC to this iphone they will not load on the phone. I get a banner error. These are all basic MP3 songs that I have stored in my Documents on my Windows 7 64Bit PC. I have checked out every online trouble shooting option online, but none have worked. Does anyone know why iphone 6 will not load MP3 files from Windows 7 PC?