If you are using a modded 3DS, you must be aware of a potential conflict called LayeredFS.
Pokémon Ultra Moon (v1.2) — CIA Build Write-Up
If dumping from an updated game, the CIA will already include version 1.2. If not, you must download the 1.2 update CIA separately (look for Title ID 0004000E001C5E00 for the US version). pokemon ultra moon 1.2 cia
Casual players may wonder: Why not just download the base game and update via eShop?
The answer lies in console compatibility and preservation. If you are using a modded 3DS, you
Note: This section assumes you own a modified Nintendo 3DS (Custom Firmware).
There is a distinction to be made between a "Full Game CIA" and an "Update CIA." Pokémon Ultra Moon (v1
General Installation Process:
In the context of the Nintendo 3DS, a .cia file (CTR Importable Archive) is a package format used by Nintendo’s official servers to install software directly to the console’s SD card. Unlike a .3ds file (which runs from a flashcart), a CIA installs the game onto your home menu, just like a legitimate eShop download. It allows for faster loading, online play (with precautions), and seamless updates.