I have been having the same problem as you have. I have spent months trying to figure it out until today. Some how I got lucky by default, my problem was solved. This is what I did.....
I reformatted my ipod and when it asked me if I wanted to sync music I did NOT click on the box. I actually haven't synced any of my play lists . Instead while my ipod was plugged into itunes I just dragged my play lists up to the ipod icon manually. All of my play lists are displayed however my amazon music went in differently. I did as someone said in one of your threads above. I put my music on a USB and transferred it by dragging the music file from there directly to the ipod icon. Now this music does not show up on my ipod in my play list menu only in my Albums. I have no idea why.
I hope my little miracle will work for you too!
I still have not checked the box in itunes to sync any music.
Indeed deleting the song from iTunes and reloading the track from the current file location worked for me. As I keep all my song files on an external drive I guess I mixed both solutions. The rrot of the roblem in my case was a song bought at Amozon. I have been struggling with the issue for months so thank you all for the tips!!!
I had this same error whilst syncing and the songs weren't from Amazon. It was driving me nuts as I could only get about 300 songs to sync before the error came up and everything froze. My work around in the end was to sync 'selected playlists, artists, albums and genres' and then select each artist starting with A, then B, etc etc and found the error came up with about 9 songs as I progressed. I found the song in my library, removed it and then re-synced with success. It does mean that I need to manually add new artists when I add them to my library but at least I got my 12,000 songs onto the iPod. It now syncs without any errors.