Facebook C# SDK installation from Nuget not working

Coding Platform: ASP.NET WebForms4.0 VB

Installed Facebook and FacebookWeb and when I run the application. I get this error

Could not load file or assembly 'Facebook.Contracts, Version=5.0.25.0, Culture=neutral, PublicKeyToken=58cb4f2111d1e6de' or one of its dependencies. Strong name signature could not be开发者_如何学Python verified. The assembly may have been tampered with, or it was delay signed but not fully signed with the correct private key. (Exception from HRESULT: 0x80131045)

What could be wrong?

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Removed the Facebook.Contracts.dll and Facebook.Web.Contracts.dll.
Working fine now.