The "Stash of Gems" discovered in the cave in Windward Isle despawned when I accidentally looted it during the battle with Shadowfae Mudcap. I received the error, "Unable to loot Item" and then it phased out. At this very moment it its permanently phased out on my character and now I can't get the "Finders Keepers" achievement. This is very unfair, that this happened without me knowing. Please help!