>>14087322
Does he have wifi turned on? There's a known glitch on the 3DS where it freezes with that error. The good news is, if that's the problem, it's got nothing to do with your cartridge - it's his 3DS.
Tell him to try starting the game with the wifi turned off. If that works (but he wants his internet back), he can probably fix it entirely by opening up the 3DS, removing the network board, and plugging it back in again until it clicks.
(The glitch doesn't normally occur on game startup but rather while browsing the main menu - but I wouldn't be surprised if Smash attempts to "phone home" every time you run it.)