"Solution exception" - installation error?

Using Grasshopper (Rhino 6, WIN 10home) with NGon extension.
When connecting a Surface to the Hexagonal SrfDivide I receive a error message:

  1. Solution exception: File or Assembly “NGonsCore, Version=, Culture=neutral, PublicKeyToken=null” or a dependency is not found. The system can’t find the file.
    I dropped the .DLL and .GHA in C:\Program Files\Rhino 6\Plug-ins. Wrong place? Where do i had it to put instead?
    Thank you!

I believe it should be in Users>AppData>Roaming>Grasshopper>Libraries
It is a plugin for Grasshopper, not Rhino.

You can get to the folder in grasshopper go to File> Special Folders > Components