One of the three Dunmer ghosts (TGCrownGhost03) in Tolvald's Crossing has four Elven maces in his inventory. The current inventory setup has two stacks of one Elven mace. Changing it to one stack of two Elven maces will fix the issue.
Note: This was reported in
Issue #20079, but the issue was apparently never corrected. Not sure if it was thought to have been a engine bug at that time or what.