Windows Phone 8.1 Assembly

Hello.

I have a problem with Windows Phone 8.1 Project builded in Unity and opened with Visual Studio 2015.

From "MyGame" solution I have reference to Assembly and Assembly firstpass. From Assemby there is reference to Assembly firstpass and it's misssing (I don't changed anything after build). I builded Universal app and as I remember I don't have this problem.

In that reference path property is empty.

I tried already: - cleaning, rebuilding solution - reinstall Unity - reinstall Windows Phone 8.1 packages from Visual Studio installer - deleting files, leaving just "Assets" and "PlayerSettings" - adding reference manually but this creating new problems, when I want to add advertising in Scripts in Assembly project error showing up on building.

Some images before clicking and after, Properties window:

And error when I want to build after adding advertising to Assembly solution: I just hide project and build names there.

How can I fix that?

Thank you.