I have ran this Dungeon several times. I chalked the first time up to a random occurrence. Now for a second time I have cleared the Desecrated Chambers section and then not had enough Animus to open the door to the next section. By the meter showing, I would guess I am missing at least 1 if not 2 kills to have the required amount to fill the Urn and open the door. I have triple checked that nothing is left alive.