People who like to use the Surprise Trade feature in Pokémon Sword & Shield need to stop using it until the game has been patched, as there are hacked Pokémon out in the wild that can crash the game if received in a trade. Pokémon Sword & Shield have a feature called Surprise Trade, which allows people to trade Pokémon with strangers so that they won't know what Pokémon they will receive until the trade has already begun.
The recent release of Nintendo 3DS Pokémon games or the Let's Go titles. It's also possible for paid subscribers to Pokémon Home to trade ten Pokémon at a time using the Wonder Box feature, so there is a lot of online activity going on with the Pokémon games.
It seems that people should stop using the Surprise Trade feature for the time being, as there are hacked Pokémon that can cause the game to crash when traded. According to Eurogamer, receiving one of these Pokémon will cause the game's online functionality to stop working, as the game will crash whenever trying to access the Y-Comm. This is due to people deliberately creating Pokémon through hacking with the capacity to crash the trading animation when sent over to another system. The issue doesn't permanently damage save files (as far as anyone is aware), but people should still be wary for the time being.
The hacked Pokémon have also been causing other issues, as Sword & Shield, including popular creatures like Bulbasaur and Squirtle. These Pokémon can now legally be traded into Sword & Shield through Pokémon Home, so people might not be aware if they are using hacked Pokémon or not.
The original games were notorious for their glitches, but Game Freak swiftly learned its lesson and did a much better job bug-testing the later games in the series. Pokémon Sword & Shield have had a few noted bugs at launch, but these games exist in an era where they can be patched at a later date to fix these issues. The existence of these malicious hacked Pokémon might be concerning to those who love to trade, but Game Freak is likely already working on a solution, especially if it wants fans to pay for Pokémon Home.
Pokémon Home is available to now. Pokémon Sword & Shield are available now for Nintendo Switch.
Source: Eurogamer