Pokemon Sword and Pokemon Shield are available today, but the two games are unfortunately off to a contentious start. No, that's not a reference to ongoing PokeDex controversy, but rather something entirely new and different. There's some evidence indicating that Pokemon Sword and Shield has a serious issue where the game can crash and corrupt the Nintendo Switch's in-use MicroSD card, forcing the player to completely reformat the card, erasing all downloaded games. Note that save files, which are stored on the Nintendo Switch console, are protected.
Little is known about what causes the Pokemon Sword and Shield crash that can lead to MicroSD card corruption. The crash appears to happen at entirely random moments, mostly during the early parts of the game. Though that's likely because most players are still in the early parts of the game rather than the area being a cause of the crash. There are a growing number of people online associating the crash with Pokemon Sword and Shield's auto-save function, though that too isn't a proven theory.
Several Pokemon Sword and Shield players say that as their crash occurred, the auto-save function of the game was going. As such, it made sense to associate the crash with Pokemon Sword and Shield's auto-save, which has notably been listed as one of the games' new controversial additions. However, the issue doesn't appear to be happening exclusively during auto-saves, as its also been recorded happening during cinematics and elsewhere.
Other potentially related details that seem important but may not be include the fact that most crashes appear to happen on digital versions of Pokemon Sword and Shield. The crashes have happened on cartridge versions of the Pokemon games, but nowhere near in the same quantity. Some also suspect that it happens more to MicroSD cards that have been formatted in Nintendo's exFAT implementation, rather than the more standardized FAT32. Others yet say the quality of the MicroSD card may play a role.
Until more information has been gathered, the exact cause of Pokemon Sword and Shield's crashes and MicroSD card corruption remains unknown. Players should, if they're able to, do as much as possible to avoid the crash, though. Things that will potentially help include buying a cartridge instead of a digital version of Pokemon Sword or Shield, turning off the game's auto-save function as soon as possible, using a FAT32 formatted MicroSD card, or using a higher quality MicroSD card over a low-quality one. Or, if even possible, not using a MicroSD card and saving the game to the Switch itself.
This is, of course, an unfortunate and severe problem. That Pokemon Sword and Switch could lead to the forced erasure of a players' MicroSD card, including their downloaded games, is a nightmare. Hopefully Game Freak is able to address the issue as soon as possible, or at least offer guidance to players through social media channels. Expect an update on the issue as soon as it's available.
Pokemon Sword and Pokemon Shield are available now exclusively on Nintendo Switch.