At the Telvanni bride part of Zainab Nerevarine quest, Savile Imayn the slaver asks you to buy clothes to dress properly Falura Llervu.
Savile Imayn suggests you to go see Elegnan the Clothier in Tel Mora for exquisite shirt, exquisite skirt and exquisite shoes, in fact you HAVE to buy from Elegnan ; any exquisite shirt, exquisite skirt or exquisite shoes from another trader WILL NOT WORK.
I was stuck few hours on this part so this hint may help someone else.