Need help !

So i am a goblin rogue and im stuck on a quest, its called ”Throw It On The Ground”, i killed the guys and i got his soulstone , i destroyed it, nothing happened, i killed him again and again destroying his soulstone everytime but still, nothing happened, i was in combat all this time so i couldnt heal and at some point i died cuz i was to low, after i came back, i killed him once again and destoryed his soulstone, this time i completed the quest but the npc that i had to turn in the quest vanished, i abandoned the quest (idk why) and now i cant redo it, and im stuck on the lost isles.

EDIT: My game crashed , i reconnected, and now every single npc on the map is gone xD