Problem with RhinoNest for Grasshopper!!!

Hi everybody!!

It's my first week with Grasshopper...I'm learning this "script" with differents tutorials in internet.

Yesterday, I found Rhinonest with Grasshopper...It's interesting but I've had some problem after installation!

I have Rhino4 SR8, last version of Grasshopper and Rhinonest 2.1 in Grasshopper.

Every time that I open Grasshopper, a massage sayd me two things:

Object: c0ac5ab21ea3ee258d55c9d4e9b4a3f4a (level 1)
{Eccezione generata dalla destinazione di una chiamata.
  TargetInvocationException}

Object: c0ac5ab21ea3ee258d55c9d4e9b4a3f4a (level 2)
{Riferimento a un oggetto non impostato su un'istanza di oggetto.
  NullReferenceException}

So, I can't used anything beacuse I don't have an instance of that object.

Anyone can help me?!?

thank you! :D