I have looted every chest in AC4 Black Flag. But the last chest at location 688,904 won't open. I walk to the chest, there is a loot option. But when I press the button to loot Edward just kicks the chest and nothing happens. Is this a bug? Please help.
You might be on the wrong side of the chest. Try walking around. Although the loot button might look activated, you need to see the indicator above the box before you can loot it.
Also make sure you're at the right box. Try locking onto the box location on your map. Then you can see your distance from it and make sure you're at the right one.