How to Avoid the Game-Breaking Index Bug in Yoshi and the Mysterious Book

Less than two weeks after Yoshi and the Mysterious Book launched as a Nintendo Switch 2 exclusive, players discovered a bug that can permanently trap a save file. Nintendo quickly confirmed the issue and provided unusually specific guidance on how to avoid it. Here is exactly what causes the softlock and how to protect your progress while waiting for a patch.

What the Bug Does

The problem centers on the Index, an in-game encyclopedia that logs the creatures Yoshi discovers across the game's 12 chapters. A talking book character named Mr. E is supposed to deliver a tutorial explaining how the Index works. If players get ahead of this scripted event in a particular way, the next time the game forces the Index tutorial to open, the screen becomes an inescapable menu. There is no button combination to close it, and no way to return to gameplay. Your save is stuck unless you have a backup from before you made the fatal mistake.

This is not a crash or a visual glitch. It is a logic trap that blocks all progress, and Nintendo has acknowledged it publicly.

The Exact Trigger Sequence

Nintendo's customer support account outlined a three-step sequence that causes the lockup. All three conditions must occur in order for the bug to fire:

1. You start researching the Bewilder Bird too early. Before the game has delivered Mr. E's proper Index tutorial, you begin an investigation of the Bewilder Bird (also called the Bird of Paradise).
2. You finish without a major discovery. You end that specific research session on the Bewilder Bird without uncovering a "major discovery"—the significant star-earning breakthroughs the game tracks for each creature.
3. You reach the mandatory Index tutorial event. The Index tutorial is a forced scene that triggers after you clear four chapters. If the previous two conditions are already baked into your save file, the tutorial screen opens and locks in place.

Crucially, the bug acts like a time bomb. You can perform the early, discovery-less Bewilder Bird research and then play for hours with no sign of trouble. The game only breaks when you later hit the post-Chapter 4 tutorial checkpoint.

The One Rule to Stay Safe

The workaround is straightforward but demands discipline from completionist players. Do not begin investigating the Bewilder Bird until you have completed Mr. E's Index tutorial. That tutorial is a fixed story event that happens after you finish four chapters.

In practice, focus on progressing through the main story for the first four chapters. You can freely document other creatures in the Index during those early hours. Just leave the Bewilder Bird alone until Mr. E officially teaches you how the encyclopedia works. After that, every creature in the game is safe to research.

What to Do If You Are Already Stuck

If you have already triggered the bug and are staring at a frozen Index screen, the only reliable fix reported by players is to load an earlier save from before you made the initial Bewilder Bird investigation. Nintendo has not released a patch yet, and no in-game workaround exists to force-close the broken menu.

Nintendo has apologized to players and confirmed that an update is in development, but has not provided a release timeline. For now, prevention is the only sure protection.