Nintendo has updated its list of Switch 2 compatibility issues to request that Super Smash Bros. Ultimate owners refrain from using the Mii Fighter characters, as they're currently breaking the game.
According to Nintendo's Japanese support website (thanks, OatmealDome), the issue with Mii Fighter only occurs when Smash Bros. Ultimate is being played online, and a match takes place between one person on Switch 1 and another person on Switch 2.
In this circumstance, should one player be using Mii Fighter, Nintendo warns that an online match may end "immediately," kicking both players out before the usual punch-ups can be had.
Nintendo hasn't explained the reason why this issue is occuring, though the fact it is limited to Mii characters may suggest there is some difference to how the two console generations handle the custom avatars — leaving the game to give up on matches instead.
Indeed, Nintendo also warns that Mii Fighter thumbnails may also not save correctly on Switch 2, pointing to some kind of compatibility problem.
"An update will be released soon," Nintendo has said, though there's no word yet on when.
Originally released in December 2018, Super Smash Bros. Ultimate is one of Nintendo's best-selling games for Switch 1, with more than 36 million copies shifted. With the series' largest player roster and years of extra content, the game has earned its Ultimate moniker — leaving many fans to wonder what might be next for the series.
Nintendo recently announced a new game from Smash Bros. series boss Masahiro Sakurai — though it's not a new Smash Bros. title. Instead, the veteran designer and director is working on Kirby Air Riders, a fresh game for Nintendo's pink puffball that's due to launch on Switch 2 later in 2025.
Tom Phillips is IGN's News Editor. You can reach Tom at tom_phillips@ign.com or find him on Bluesky @tomphillipseg.bsky.social
