[Quest Bug] Twin Adder Quest

Date & Time: September 21, 2013
Frequency: Once
Character Name: Coral Ferrinas
Race: Miqo'te
World: Balmung
Class/Level: Lv.50 Bard
Area and Coordinates: New Gridania, Adders' Nest
Party or Solo: Solo
NPC Name: Vorsaile Heuloix


Steps:
1) Took the quest Lv. 50 In For Garuda Awakening (Main Scenario Quest) in the Walking Sands.
2) The quest required me to attune to the beastman Aetheryte in Natalan.
3) Teleported to New Gridania and spoke to Vorsaile Heuloix to turn in the Quest Lv. 50 Twisted Believe (Twin Adder).
4) Quest Complete, initiating the next quest of the Twin Adder.
5) Quest Dialogue continues, the dialogue is asking to attune to the same Aetheryte in Natalan. However, no new quest listed in journal, and no new quest is listed in duty list.
6) Proceed to attune to the Aeytheryte in Natalan.
7) Defeated Garuda Hardmode.
8) No further quest interaction with Vorsaile Heuloix. Unable to continue the Twin Adder Quest, therefore unable to progress through the ranks.

Please Advise.

Although I am Maelstrom, I wanted to see if this might help.

Vorsaile Heuloix, only starts 2 Twin Adder Quests. Both which you said you turned in (Shadows Uncast-Twin Adder & Twisted Beliefs-Twin Adder). However, Vorsaile is also involved in the In For Garuda Awakening-Main Scenario Quest. I think you need to turn in the Main Scenario Quest. Vorsaile doesn't have any more Twin Adder Quests for you. You can look at the information on him here: http://ffxiv.gamerescape.com/wiki/Vorsaile_Heuloix

I think that because you had 2 quests dealing with him, one that ended with him (Twisted Beliefs for Twin Adders) and another that only involved him (In For Garuda Awakening-Main Scenario), you got confused. He shouldn't have any further Twin Adder quests, and you should only need to hand in the Main Scenario one.

PS- If the Main Scenario one is also bugged, try to make sure you have room in your inventory. Sometimes the Main Scenario Quests bug out when your bags are full.