No 100% for me. Cant enter Revenclaw corridor

[juancitum]

In the room where you can enter each of the four houses. For the revenclaw one there is a bird with the head missing.  I checked a couple of video guides and in those, the head is on the floor, you just have to pick it up and place it, then the door opens. In my game there is no head. I cant do anything. The things that are beyond the door are the only things missing from the 100% and the platinum trophy. 

 Am I missing something? Or its just glitched? 

So sad. I feel like breaking the disc.