Basically, if you're going to spend launch day with your Switch 2 playing Super Smash Bros. Ultimate, just don't pick Mii Fighters.

Mii Fighters Shouldn’t Crash Matches in Super Smash Bros. Ultimate Anymore One thing to note is that this update only addresses one of two known issues with Mii Fighters on Switch 2.

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.

As explained by Nintendo of Japan, the Mii Fighter character in Super Smash Bros Ultimate can now crash everyone’s game when used in a match between an OG Switch player and a Switch 2 player.

This specific problem with Super Smash Bros. Ultimate isn't the worst, but it's annoying for anyone who experiences it, especially if their preferred fighter is a Mii Fighter.

Nintendo’s Warning on Playing Mii Characters Players should listen to Nintendo and temporarily avoid selecting Mii Fighters during Super Smash Bros Ultimate online matches.

Mii Fighters are breaking Super Smash Bros. Ultimate matches on the Switch 2 It's an edge case, but a fix is on the way from Nintendo.

Mii fighters in super smash bros. ultimate are off limits (For now) As a follow-up, @OatmealDome notes that Nintendo is asking players to refrain from using Mii Fighters in online Super Smash Bros ...

Super Smash Bros. Ultimate Super Smash Bros. Ultimate's Nintendo Switch 2 journey isn't going too smoothly as Nintendo asks "please avoid using Mii Fighter in online play as much as possible" News ...