An "updated" file usually refers to a game ROM that has the version 1.5 patch already applied, saving the user from having to manually install the update after loading the game. Current Status of Online Services

To understand why a "decrypted" file is necessary, it helps to understand how the original Nintendo 3DS hardware handles data. What is a Decrypted File?

Do not do this manually. It is much easier to install the update as a separate .cia (Method 1 or 2A).

Mixing regions will result in the emulator failing to recognize the patch. The game will remain at version 1.0. How to Install Pokémon X Update 1.5 in Citra

This update (version 1.5, internally v3584) was the final major patch released for Pokémon X and Y in late 2013 / early 2014. The "decrypted" version means the update CIA (CTR Importable Archive) has been stripped of console-specific encryption, allowing it to be installed on any jailbroken 3DS (via custom firmware like Luma3DS) or used with emulators such as Citra.

Nintendo 3DS software is strictly region-locked. This regional formatting carries over to emulation architecture. When sourcing your Update 1.5 file, you must match the region of your base game. Base Game Region Required Update Region Compatibility Outcome (North America) USA Update 1.5 Works perfectly ; unlocks full patch features. EUR (Europe/Australia) EUR Update 1.5 Works perfectly ; unlocks full patch features. USA (North America) EUR Update 1.5 Failure ; emulator will reject the patch or crash.