Hello, I changed my name Minecraft's name on the website of Mojang, and since I cannot open any more a locked chest on my island. Fortunately, I have still access to my island. Can you remove the sign? PS: English is not my mother tongue, and I am sorry if my grammar is bad.
You will need to ask a mod in game to break the locks. Either message a mod whos name is in red (full or super mod). If you cannot use /trust you will need a supermod.