Bugged quests in the Steam version

[odebenoist]

I had three unfinishable side quests :
Artridis' Rescue : when I bring the eggs back to the griffin, nothing happens
Pirate's Crops : same thing when bringing the 5 herbs to the pirate
Cursed Treasure : wheter I open the treasure in the cave or not, the pirate outside can't realize it

I had some others which I can't remember where the quest log wouldn't update unless I use the save and reload tip

Sadly this tip doesn't seem to work for the Mehgard pilot and now I'm stuck in the main quest.

Maybe there's a way to change my saved game in a 1.6 version just for this part (steam version) ?
Maybe there's a place in Mehgard where the save and reload tip would work best in order to make the pilot appear ?

Thanks