I looked up how to get it and u have to move a shelf to reach it. the issue is the was never a shelf for me to move. the window was already unblocked and no shelf was present. i dont know if that hut is part of the quest tossing and turning. i found kassandra at the cursed church before i went to kiltaraglen (i prefer to explore the area before starting the story), which finished the tossing and turning quest and started the night and day quest. so am i unable to get this treasure now or is there a fix?
Edit: Left and came back and the shelf was there.