Pokémon Ultra Sun update, released in February 2018, is a critical patch primarily focused on fixing game-breaking bugs that affected competitive play and online stability. For users on custom firmware (CFW) looking for this update in .cia format, it is often listed under "World" or "Region Free" categories on community databases because the update data itself is largely universal across regions. Key Features & Bug Fixes in v1.2
If you downloaded a .cia file on your computer from a trusted archive: Turn off your 3DS and put the SD card into your PC.
v1.2 World.cia (verify the Title ID).