i dont know if this is a bug or not, i cant click "E" in tree puzzle but i did in last try and got 70%. i really understand that puzzle how to get all closed eye or red eye and maybe to get some of those blue gems :D
i do cheat, i watch aza466 playthrough about the key and stuck at loading point in gamingwithbliss comment. everything else is completed by myself
PS: its a spoiler if you want to finished by your self