Visual Studio 2017 won't load .NET Framework references in .NET Standard library

Question

I\'ve installed Visual Studio 2017. I have a class library in the new .NET Standard format, which is able to be used by both .NET Framework and .NET Core. But when I go to <

Answer 1

On my side, I've tried all the solution presented before but the solution was simply install NuGet package for Microsoft.CSharp.

After installation just clean the project and restart your IDE.