I have version 24.2D, finished quests for Ivy, Janet and Lily and didn't see the dungeon even once. Also, is it possible to get ancient sap in this build?
You must ask barkeeper about Reynard and his friend, next, you ask them about stealing from customers, they will give you a lockpick and a silver crest, then you must find a ancient map (i forgot where did you get it) then a tomb should be at the top right corner of the map. Enter it, then place the crest at the center of the rock in the triangle-looking place to release Erza. Do what Erza says and then you will able to get to the dungeon