When I was about to change my username, I'm going to one of the buildings on my world, I found chests (and inventory) got empty. Paintings and Item Frames are dropped. No flowers in pots.
MC-54939
Chests and Inventory turns empty upon changing username.
Resolved
Invalid
0
(Unassigned)
Unconfirmed
Minecraft 1.7.9, Minecraft 14w18b, Minecraft 14w19a
Retrieved
It's not possible to change your username. Also, downgrading a world isn't supported and can cause data to be corrupted. Invalid.