Oh okay, so there's no failed quests at the moment thx for the info.When Tink designed that quest it was part of Vampire Update Part-1. The raid was in Update Part-2. Sadly that means the game expects you to finish that beforehand.
Also the "Failed Quests" is a remnant of the system because Tink hasent actualy put failure in the game. You're supposed to be able to complet quests at you're leisure...
Its not something game breaking but i do hope it get patch in the future, it just stuck there as an incomplete quest with no serious consequences for now.