Ok I understand there is a bug pertaining to the dagger racks inside the bedroom of Hjerim. I placed the Keening dagger in one of those display cases. Is there any way to retieve the dagger or get another Keening dagger to spawn so I can complete the Arniel's Endeavor mission? Thanks in advance for any helpful information.

For a Keening replacement

~Player.AddItem 6A13C 1

Awesome many thanks!!!