Normally, Nintendo 3DS games are encrypted to prevent them from being played on unauthorized hardware.

If you are planning to use a decrypted version of Pokémon Sun, here are the technical details you need to know:

: These have had their security layers removed. They are typically found in .3ds format and are required for emulators like Citra . Without decryption, the emulator cannot "read" the game data. Essential Specs for Pokémon Sun (USA)