How do I unlock a gold chest on a floating island?

My floating island has a locked gold chest, and I've updated to version 1.2. How do I unlock it?

Solution 1:

Gold chests require a Golden Key

Gold chests on floating islands and in the Dungeon require a key to open. These keys can be found in the Dungeon, either in normal chests, from killing Dungeon Slimes, as a rare drop from any other Dungeon enemy (1/65 chance), or in Pots in the Dungeon (1/40 chance).

But I thought floating island chests were unlocked?

For the initial release of Console Terraria, chests on floating islands were locked. It wasn't until the 1.02 Console update (making it the equivalent of the PC 1.2.1.2 update) that floating island chests were no longer locked.

But I'm fully updated!

Features such as chests and their contents are determined at the time a world is generated, and are never altered by updates. If you generated your world in an older version of Terraria, those chests will still be locked after an update. To be sure you get all the features for the newest version of Terraria, particularly features of the world (e.g. Crimson or the Snow Biome), you'll need to generate a new world after you update.