Gamers playing Pokémon Sword and Pokémon Shield should be wary of using the Surprise Trade function at the moment. According to Polygon, many players using Surprise Trade have reported issues with the function including game crashes and general connectivity issues. According to Polygon, the reason why this is occurring is because some hackers are creating bad Pokémon with custom firmware that cause the game to play the trade animation repeatedly until the game crashes.
POC for the Surprise trade Crash! pic.twitter.com/o6CtylL0mo
— thecommondude (@architdate) February 12, 2020
The other issue comes after the game crashes, once players reload the game, the game will no longer allow players to use the multiplayer Y-Com feature and will crash if players attempt to use it. Some people on Twitter have also released a PSA stating that if players receive a Pokémon through Surprise Trade that causes the game to crash, when players reload the game “Your save data won’t be corrupted; the Pokémon you received from Surprise Trade is waiting to be received and will crash when the game tries to receive it. Can’t launch any online features. It’ll also crash if received via trade, but only once — just release it afterwards.” This means that a potential solution to this issue is that players can release the bad Pokémon after it crashes and the issue will resolve itself, however this hasn’t been confirmed.
Your save data won’t be corrupted; the Pokémon you received from Surprise Trade is waiting to be received and will crash when the game tries to receive it. Can’t launch any online features. It’ll also crash if received via trade, but only once — just release it afterwards.
— Kurt (@Kaphotics) February 12, 2020
Unfortunately, there is no patch as of yet and Nintendo has yet to respond to the issue, but it is likely that a patch will be created soon. However, players looking to transfer Pokémon can do so right now because just today, Pokémon Home has released worldwide on the iOS and Android, as well as on the Nintendo Switch.