Trying to use rotate family custom node

Hi I am trying to use the custom node rotate family but get the following error message. I am using dynmo 7.1. Anyone know a way of solving it?

Warning: IronPythonEvaluator.EvaluateIronPythonScript operation failed.
Could not add reference to assembly LibG

railing twelve

maybe there is a path missing?

something like that:

path = r’C:\Autodesk\Dynamo07\Dynamo0.7’
exec_path = r’C:\Autodesk\Dynamo07\Dynamo0.7\Core\dll’
sys.path.append(path)
sys.path.append(exec_path)

thanks for the reply, i went about it different way and built a family with a rotation parameter in but thanks all the same