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.
Resolved a rare case where the game would crash if an evolution item was the last item in the bag and was used. Pokemon Sun: Update 1.2 3DS (WORLD) CIA
Patched a well-known glitch that allowed players to complete all Poké Pelago activities instantly by manipulating the console's calendar during a month change. Update 1