error -12894 when trying to play certain songs on iPod/iPhone
I've recently transferred files from one computer to another and have added those files to my iTunes library. These files appear and play on my iTunes on my PC without any problems, however, some songs won't play on my iPod touch and just skip the song to the next one which means that whole albums don't play. On my iPhone 5s, when I try to play a song a message appears saying "The operation could not be completed; An unknown error occurred (-12894)".
Not all of the files I transferred in this way have issues: some files play fine on both the iPod and iPhone 5s but others don't.
I'd appreciate it if someone could help.
Thank you.
iPod touch 4th Gen - iOS 6.1.6
iPhone 5s - iOS 8.4
iPhone 5s, iOS 8.4