Update: Many Japanese players reported that they lost saves with this bug, so I initially got confused, my bad. Technically, it shouldn't be possible because the Switch only stores game saves on the console's internal memory. And you normally can't copy saves from the internal memory to your SD card and then delete the saves from the console's memory. You can only copy saves from the internal memory to the internal memory of another Switch console nearby. Meaning it technically shouldn't be possible for this reported SD card corruption to affect game saves, you'd only lose the games you downloaded, the videos and the screenshots you took. There are definitely players who said they lost their saves though, so there seems to be another issue which causes this.

Update 2: I've read more Japanese tweets, and as far as I checked players who claimed to have lost their saves actually only lost their Pokemon Sword and Shield save, and it's because the game crashed with that supposed error/bug, before they could save or while they were saving. So yeah this possible bug shouldn't have any incidence on saves from other games.

Moreover, the issue has been confirmed to stem from the SD card themselves. Users on sites such as github have been mentioning this issue for a few months now. Basically, if you use an SD card formatted in ExFat instead of Fat32, certain games, like Pokemon Sword and Shield, can end up making the SD card corrupted. The solution is to only use cards formatted in Fat32.

Original article

Pokemon Sword and Shield is available everywhere now and everyone's enjoying it, happy to get into Pokemon again. However, it looks like the games have a horrifying bug that can delete saves, the worst nightmare for any player in the world.

These past few hours, multiple players around the world explained on social media how after they bought and played Pokemon Sword and Shield, they received an error that ended up corrupting all the data on their SD card. This includes downloaded games and game saves. If you own a Nintendo Online account and didn't deactivate the Cloud backup, you could always get the saves back. However, if you didn't, it seems like the saves will be lost forever.

Players initially reported how the bug only affected the digital version of Pokemon Sword and Shield, or that deactivating Autosave would stop the bug from triggering. However, later on, more players, who got the physical version, mentioned they got the bug as well, like this Japanese player:

In the thread, they most notably mentioned how they had autosave deactivated, and own the physical version of the game. They also explained that the bug triggered, not while saving, but when throwing a Pokeball.

Multiple similar tweets can be found, like this Japanese player who said they got the bug and their SD card corrupted even with autosave deactivated:

One Japanese Twitter user compared the situation to the infamous "Phantasy Star Online 2 HDD Burst" incident. In September 2013, a bug in the updating process for Sega's online RPG ended up deleting data on the HDD of many players. Sega reported that around 20,000 players were affected. The company publicly apologized about the incident, monetarily compensated the players with both real money and in-game money, and paid for HDD data recovery services. This could give you an idea of what could happen with this incident.

In precaution, assuming the bug is real, you should avoid playing Pokemon Sword and Shield and wait for future developments. Nintendo will probably publish a message regarding these player reports soon. We'll be sure to update you when something moves.