iPod Classic 1429 Error solved!
I had errors in restoring my faulty iPod Classic 40GB: error 1429
I tried on a MacPro 213 / Big Sur and a MacPro 2008 / El Capitan, nothing.
Impossible to reformat or restore, continuous crashes, and so on.
I searched the community but I found no solutions, until I discovered this Italian page:
https://it.technobezz.com/iphone-apple-errors-fixes/
In the 1429 error chapter I found:
"Change the user account you are currently using on your computer. Make sure the other user has admin rights."
On the MacPro 2009 / El Capitan I changed the user login to another with administrator rights, I connected the iPod to iTunes and this way I immediately can restore it!
So I decided to write this message to help other iPod Classic users with the same issue, that seems to be a very common defect.