The Experimental Construct Part in Bastion that requires finding the Unstable Construct Anima is just coming up with an empty loot window when clicked on with the necessary item gathered. Had another player do this and confirm the same problem. Wowhead pages has other players reporting the same.
same problem.
Same problem
Same problem… 
Same problem love how this game is full of bugs. Love the fact that blizz is ignoring it.
Hope they can just send us the contents of that chest in the mail… They should be able to check who opened it