After following the rather dark line of Slytherin’s quests with Sebastian, you will get a quest called “In The Shadow of Time”. The quest will send you to some catacombs in search of a relic. You will eventually get to a room that contains a pile of bones on an altar in the middle of the room. You will be able to use a levitation spell to move the bones but there seems to be a bit of an issue.
There is a doorway across from the altar that you need to move the bones over to in order to build an archway. The revelio spell will show where the bones need to go. If you try to place the bones on the spikes at either side, you may find that nothing seems to happen. You can try several times and nothing at all will happen. This appears to be where the glitch lies.
The video below will show you in greater detail on how to get around this issue. Putting all three skeletons on the arch is what you are supposed to do. Don’t make the same mistake I did bringing the skeleton elsewhere and make it impossible to bring back.
There are three sets of bones that you will need to find. Pulling open the boxes around the room will reveal two more sets of bones to use for the arch. You will need to swing the bones around quite wildly to get them to stick to the archway correctly.
The door will open once you have all three of the skeleton bones attached to the arch. If you make a mistake or the bones glitch out completely, you can go into the settings menu and reload a previous game save to fix the issue.
