When you try to make an offering to the frog spirit, either with money or the frog bone, the dialogue will get stuck and soft lock the game.
How do you fix this and get past it
This bug was fixed in a Hotfix in v7.06. Unfortunately that version is not currently available here. Contact the developers for more details.
More info, supplying Troll head as suggested, this quest is the only one that cant be done due to this, while it seem to not softlock the game, it does not compleate either.
Side note, if empty text box is shown, try go back as this will not allow you to progress but going back sometimes skip the empty text box.