Has anyone ever seen this error before? Started a few months ago and now 99% of my music won't copy across to my iPod. I've reset my library, deleted and re-added all music, but still it won't copy. happens on both an iPod Classic 7th Gen & and iPod Nano 7th Gen. Error message appears in iTunes (latest version) on OSX Mavericks. All music is stored on an external NAS. I'm at my wits end with it! Any help appreciated.