I just finished the last hunter, and I only have 7/8 keys too. I hope that Ubisoft / Massive fix this soon.... Quite demoralizing to get all of the masks, and cannot get the 8th key... I did place a support ticket as well.
Hey Deltium, Have you tried killing the last hunter in a co-op game in another player's world? That can cause the key to drop.
I have still not received my final key after killing all the hunters, could you please direct me to where or what I have to do to get my last key
