I have done A Formal Dinner Party three times (because it doesn't give group rewards, in spite of definitely needing a group to do). One of those times the 4th clue did not drop. I cleared every single killable mob in the zone: in the tunnels under the lab, the lab, the library, behind the secret bookshelf in the library, the hallways, the bedrooms, both sides of the crypts, the "study" (weapon racks) and the ritual area (both sides). Ranger track was empty, save for a few grey corpses, and the quest NPCs. Can I suggest that the easiest "fix" would be to only make turn-in steps 3 and 4 optional? It is possible to positively identify the killer with just two drops, it happens fairly frequently. If somehow the player has not figured it out by step 4, at least they've narrowed it down and can try their luck. Obviously it's still better if all 4 items are guaranteed to drop, but it's usually unnecessary.
Ive never had them not drop. You might want to track on the top level and then again in the den and in the ritual room. It might be that track does not stretch far enough to get the whole instance.
Same thing happened x 2 with me. But both were requested by the same character. I only needed one more weapon item and could still see mobs on track but no way to get to them. So lost that one. Next time, on further exploration I found the bedrooms have a couple secret doors and down where the weapon racks are is another one door off to the side. But still did not get the drop and no further mobs were on track. I eliminated the track distance possibility by going thru the entire zone again. Every time I do this I make sure I clear the weapon racks and have never found the items in those. But because that is the answer everyone gives, I make sure to get it out of the way. Then I switched and had another character ask for it and finally found all the items. Don't overlook the bats and the sleeping mobs in the crypts.
also make sure you are doing the back half of the library (through the bookcase/door), the lab, both passages off sisters area, all bedrooms in that area, the room on the way to the east side same area, and all the mobs on the way down to devlin/roley/tris including the weapon racks. i've done this mission many, many times and its always had all the drops present.
Sure I fully cleared the weapon racks (aka study), and the ritual area. And behind the bookcase in the Library. I've done the quest 7 times now, it bugged once. I've also shown you can positively identify the killer on just one drop: some items have two classes on them, and one of those two classes isn't at the table. I'm all for forcing players to do the whodunit, but if the quest bugs you lose 40mins.
Never seen a clue not spawn, and I've done it 500+ times (2 or 4 times per day for the past 6 anniversaries). Most common cause is missing the sleeping npcs in crypt (one of which you can't see at all until you stand right on top of it), or the weapon racks (easy to think there are only 2 racks, there are 4), or missing the 'secret' wall in library. Ballroom: Any of the dancers, and only the dancers. Library: Any mob in the library (including the deep orc who loves to flee into the locked door and then you're SOL, have to fade/camp/gate/fd and hope he resets), also can drop from the single mob in the ballroom guarding the door to library. Lab: Any of the 8 mobs in lab. The deep orcs (0-2) guarding the lab entrance never have any clues. Crypt: Any static mob on either side of the crypt (~7 in each). Roaming bats never have any clues. It's possible to agro the other crypt through the wall, and mobs can (rarely) get lost god-knows-where. Bedrooms: Any static non-named mob in the two bedrooms (3-4 in first room, 1 in second). Sometimes named spawn but don't think I've ever seen a clue from them. Roaming deep orcs in hallways never have clues, static mobs in the hallway (connecting bedroom 1 and 2) I don't recall ever seeing a clue from, but don't really pay attention. Study: Any of the 5 shadowmanes (4 in room AND the single shadowmane at the dead end). Can also spawn in one of the 4 weapon racks. Ritual Area: Any static (2 orcs and 4 gargs in first room, 1 orc and ~6 zombies/drachnids in second room). There's a roaming drachnid that has a chance to spawn, but never seen a clue from it. TL DR Kill the sleeping mobs in crypt that you can't see, and the weapon racks. If you're running with lower level chars make sure your DS isn't doing all the damage. Originally you didn't need the clues, could just guess and kill. That was fixed, and it's unlikely they revert this to make it easier. Technically there's a wooden splinter only usable by a zerk, always fun when that's your first clue drop.
