i'm having the same problem,they keep saying open the casket,but yet I can't fine anything else.when you hit the hunt button it say nothing else can be done here..

I'm stuck on
The Treasures of Mystery Island


I'm stuck at the cave entrance/Waterfall/jungle waterfall. I can't find the piece of gold cup and a piece of stone is missing.help me please.I don't don't what i did wrong,i did everything it said,