We've already reported on the Pokemon X/Y glitch that causes your game to freeze if you save in Lumiose City. The thing is, what do you do if you're suffering from the glitch right now? One Reddit user has come up with a method that worked for him. Keep in mind that this is in no way an official fix, so try at your own risk.

Step 1: Load your game.
Step 2: As the game loads wait for the music to start.
Step 3: Mash the home button until it works.

Link