The new sm 4 sh ones can be perfect controllers too , you just find more perfect old ones . Controllers are a lottery if they haven ' t been tested and verified already <| sep |> Jeez you need to read up on ya bird law man <| sep |> Are you really the machine that can answer any question in existence ? <| sep |> That ' s really odd . Could maybe be a bad sector on the SD card or something , I guess ? So it does fine until it tries to readwrite that sector . I ' m completely guessing here , I don ' t know much about SD cards or data storage in general . Do you have any other way of doing the transfer besides wireless ? Access to a computer with an SD slot or a USB adapter you can stick an SD card into that you could use to copy the data over ? Or at least check that the SD card ' s working on a computer . Maybe at a library or something , if you don ' t have one at home ? The ideal thing would be if you have a microSD to SD card adapter as well , so you could move all your stuff to the new microSD card before doing the transfer . Then during the transfer you can tell it you ' re using a microSD card and it ' ll just tell you when to move it over . If you can do this , I ' d recommend this guidegaming . org . ukblog 20150115 upgradingyour 3 dssdcard , which seems to prevent the misplaced data that occasionally seems to happen for no apparent reason when moving 3 DS data to a new SD card .