From the Patch Notes:

Entry Requirements
Quest Maniac Manor
Required Level Level 50
Location Western La Noscea (X:26, Y:26)
NPC: Lauriane
Prerequisites Players must first complete the main scenario quest "The Ultimate Weapon."
The correct location of the Maniac Manor quest is in Mor Dhona (X:22, Y:8), in the same tavern in which the Copperbell Mines HM quest "Out of Sight, Out of Mine" can also be found.