Update 1.2 for Pokémon Sun on the 3DS is a significant patch released to address critical bugs and is required for all online features like trading and battling.
Corrected an issue where items could sometimes be given to Pokémon Eggs. Installation for Modded Systems (CIA) Pokemon Sun: Update 1.2 3DS (WORLD) CIA
This update primarily targeted several glitches that could disrupt gameplay or be used for exploits: Update 1
If you are using a modified 3DS with Custom Firmware (CFW) , there are specific considerations for installing the update via CIA: Pokemon Sun: Update 1.2 3DS (WORLD) CIA
Fixed an issue where Pokémon would become unable to attack or switch if they were knocked out by Spiky Shield damage while using Sky Drop .