Since the release of quite vaguely described last patch, many Super Smash Bros. Ultimate players are searching through the game to see what gameplay was changed for each of the fighters. It appears despite there already being an update that there is game-breaking bugs present in Smash Ultimate.
This bugs is so bad it has even been picked up by GameXplain which is the above video showcasing how it is done and what happens when it occurs. The glitch revolves around Isabelle and Villagers 'pocket' (B) ability which for those that don't know can catch most (if not all) physical objects or projectiles.
Isabelle and Villager begin the glitch by Villager catching a forward air slingshot from Isabelle. Villager then proceeds to throw back the projectile and Isabelle then catches it, after Isabelle throws it back to villager and he catches it again the game soft crashes with an error message "The software was closed because an error occurred". GameXplain can confirm that this glitch only works with Isabelle, Villager and that specific projectile. So, if a player attempts the glitch with two Villagers or two Isabelle's the glitch will be ineffective. Since this glitch is literally breaking the game we should be able to safely assume that it will be mended within the next games update.