after completing the main campaign, the dark and light post game missions and the Ergo Sum, i am still missing the Arcane Needle Melee ability on my warlock, i have tried to re-enter the incision in The Blooming but the chest that you should get it from is not spawning? i have checked and i have got the darkness melee on my Titan so cant see why it wouldn't appear for my Warlock? Any help on how to resolve would be appreciated