In the Falls area i found 20 of the required daggers in this quest before talking to the eleriiza (or whatever her name is.) and the last dagger is found with the skeletons that attack the tavelers, but the quest auto-fails after i talk to her and continue the quest "a spring run dry" so for all out their confused about this quest its not you its the game.

P.S. This quest reminds me of that one quest from kingmaker where you had to Schower the map for random suff to open a cyclops tomb. Granted this is not nearly as bad as that but it has the same feel.

What OS and what version of the game are you running?

Did you send an in game bug report via ALT B?

Win 7 v1.0.4d.02
and yes but i dont think that it being Win 7 would make one specific quest to not work. But i could be wrong.

One can be stunned by what actually can lead such a game to bug or even break.

A lot of issues I have read about, related to loading, have less appearances e.g. when the game is installed on SSD compared to HDD, and such alike.

An update has fixed this bug, im happy that owlcat has fix it so quickly.