If you're trying to solve the Zero Hour floor puzzle in Destiny 2, chances are you're trying a legend run, but didn't realise that the combination changes depending on the difficulty and the elemental threat. For those that don't know, the new, or technically old, Zero Hour exotic mission has a section where you have to walk through a room full of tiles in a certain order—pick the wrong one and you're cooked, literally.
Usually, there's a diagram showing the route on a wall in the vault itself...