Cant finish act 4

i am stuck at act 4, i killed all the bosses but the quest keeps asking for weapon pieces,

i am killed the bird the prisonner and the mermaid

same, done all of the weapon pieces twice, and it still won't let me progress.

Hey, I'm experience the same.

Killed all 3 bosses and cannot procede to Arastas.

On the Map i can check that the icon for both Diamora and the Bird are crossed, the only one that doesn't appear crossed is the prisionner.

Already re-did the bird twice and the prisionner at least 5 times.