Fixed a bug that sometimes prevented Pokémon received via Mystery Gift from being registered in the Pokédex. Managing CIA Files and Installation
Search for "Pokémon Ultra Sun Update" or find it in the "Settings/Other" -> "Updates" section. Select the update and download it.
Pokémon Ultra Sun is an enhanced version of the original Pokémon Sun game, released for the Nintendo 3DS in 2017. The game received an update patch (Update 1.2) that improved stability and fixed various issues. This guide will walk you through the process of installing the update and provide information on CIA (CTR Importable Archive) files, which are used for importing games and content on the Nintendo 3DS.
The 3DS hardware was aging by 2017, and Game Freak pushed it to its absolute limit with Generation 7.
Be aware that after installing version 1.2, any Battle Videos saved on previous versions can no longer be played or shared. File Specifications Pokemon Ultra Sun: Update 1.2 3DS (WORLD) CIA ... - Ziperto
This information expires once printed. Please always refer to the online version for the most current information.