Well, not all things can be without some kind of error! The Japanese version of Kingdom Hearts 3D [Dream Drop Distance] seems to contain a glitch that can halt progression within the game, and while it seems to happen only under specific circumstances, it has been experienced by enough people to make it a concern of Square Enix. Square Enix's Online Support site updated with the acknowledgement of the bug and potential fixes.

SQEXGAL summarized the bug in the quote below:

It looks like there is a glitch when you play as Riku in a certain part of the World That Never Was. If you drop as Riku in a certain spot where stairs appear but before you can go up them, when you return you will be locked out and and unable to progress, thus the warning.

Square Enix suggests that you work from a save before the bug appeared, or have used your second save slot at a point before dropping to Riku. More than likely, the bug will be fixed in the localized versions of the game!

Does this bug fascinate you? The forums are just the place to do so!