Earlier this week it came to light that the latest Pokémon games contained a rare save bug at a certain location in the game that locked the game down. Today Nintendo released a title update for Pokémon X and Y that fixes the bug and makes the game safe to play again. The software update is now available to download from the 3DS eShop. All you have to do is boot up the game, go to the game updates menu and download the update you see listed.
The rare save-corrupting bug that affected some players of Pokémon X and Y for the 3DS occurred when players attempted to save their game outside in Lumiose City. A map showing where this bug can occur can be found at this link, though the language on the map is in Japanese. Those affected by the bug reported that their save files were made completely inaccessible. The bug affected both the physical retail versions of the game as well as digital purchases.
Pokémon X and Pokémon Y launched worldwide last week, selling over four million copies in its first weekend on sale.