I'm getting sick and tired of the same problem. I have an ipod Classic 6th Gen (120gb) and today tried syncing to itunes 12.0.1 after years of hassle free use. itunes is now crashing, causing errors, partially syncing in both auto and manual transfer settings and is generally dysfunctional.
I've restored the ipod to factory settings (obviously thus wiping my device library), I've uninstalled and reinstalled itunes. I've tried all the various suggestions online. Still I keep coming up with a variety of 'unknown error' messages; 69, 53, 163 etc.
Is there any fix - can taking it in to a store even resolve this? I am loathe to buy a new device when the device is fine and I'm p*ssed off with Apple for releasing a new version of itunes when there are still so many people using older versions of their devices - it comes across as cynical marketeering that requires us all to buy the latest hardware to keep pace with the software....
Please help!