InternalsVisibleTo attribute isn't working

Question

I am trying to use the InternalsVisibleTo assembly attribute to make my internal classes in a .NET class library visible to my unit test project. For some reas

Answer 1

Previous answers with PublicKey worked: (Visual Studio 2015: NEED to be on one line, otherwise it complains that the assembly reference is invalid or cannot referenced. PublicKeyToken didn't worked)

[assembly: InternalsVisibleTo("NameSpace.MyFriendAssembly, PublicKey=0024000004800000940000000602000000240000525341310004000001000100F73F4DDC11F0CA6209BC63EFCBBAC3DACB04B612E04FA07F01D919FB5A1579D20283DC12901C8B66A08FB8A9CB6A5E81989007B3AA43CD7442BED6D21F4D33FB590A46420FB75265C889D536A9519674440C3C2FB06C5924360243CACD4B641BE574C31A434CE845323395842FAAF106B234C2C1406E2F553073FF557D2DB6C5")]

Thanks to @Joe

To get the public key of the friend assembly:

sn -Tp path\to\assembly\MyFriendAssembly.dll

Inside a Developper command prompt (Startup > Programs > Visual Studio 2015 > Visual Studio Tools > Developer Command Prompt for VS2015). Thanks to @Ian G.

Although, the final touch that made it work for me after the above was to sign my friend library project the same way the project of the library to share is signed. Since it was a new Test library, it wasn't signed yet.