The required disk cannot be found

I changed the settings on my iPod nano so that it would sync songs from a new playlist I created. However, once I did that and hit "Sync", it kept telling me that the iPod cannot be synced because the required disk cannot be found. I tried ejecting and plugging in my iPod again, however, every time I plug it back in the settings go back to the original, and I have to change them to sync to the new playlist again. But every time I do this, I keep getting the same error message (The required disk cannot be found). So I deleted the old playlist entirely and as a result, all the songs on my iPod disappeared and it now keeps giving me a message that the playlists to sync to no longer exist. And if I try to change the settings so it would sync to the new playlist, I once again keep getting the message that the required disk cannot be found. Can anyone help?