So let's say that you've region changed your 3DS (example: JPN to USA) and you try to go in the eShop and/or Pokemon Bank on the USA version but then you get an error code that says 007-2001. This is because your serial number in Nintendo's servers are still in the other region (JPN). In order to fix this, you need to go back to the original region your 3DS was in and delete your Nintendo eShop Account from Settings/Other. This will delete the serial number's region in Nintendo's servers. https://en-americas-support.nintendo.com/app/answers/detail/a_id/74/~/how-to-delete-a-nintendo-eshop-account
Once you deleted your eShop account, go back to the region you wanted to go to and access the eShop/Pokemon Bank from there and now you won't get that error anymore. (The serial number of your 3DS is now in the correct region on Nintendo's servers). I've joined the Discord server and the Kurisu bot helped me solve this error I had on my region changed 3DS. Join the server here: https://discord.gg/C29hYvh
Once you deleted your eShop account, go back to the region you wanted to go to and access the eShop/Pokemon Bank from there and now you won't get that error anymore. (The serial number of your 3DS is now in the correct region on Nintendo's servers). I've joined the Discord server and the Kurisu bot helped me solve this error I had on my region changed 3DS. Join the server here: https://discord.gg/C29hYvh
