Error loading a 3.0 framework dll (WFC)

Hi! I am trying to load a managed dll into my project. C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.0\System.ServiceModel.dll

Its an Empty project. I paste t$$anonymous$$s dll into my Asset/Plugin folder. I compile for Windows8 (Universal App)anyway it fails with all SO. I change API Compatibilty level to 2.0. It seems its load without problem. As soon as I play Unity the following mistake appears:

SpritePacker failed to get types from System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089. Error: The classes in the module cannot be loaded. UnityEditor.Sprites.Packer:GetSelectedPolicyId()

I do not know what its happening!