Help with essentia code...

I got the code from http://pastebin.com/qhFezYAP and cannot make it work for me…

The error I'm getting is 37:Argument slot cannot be null. I have the ethereal essence in the crystal chest, with a golden chest under it. I'm lost when it comes to this…

That code's broken, per the discussion it came from. Keep scrolling down that page for the completed version.

Much appreciated. After some tinkering, I got it to work with my setup. Thank you!