You must add a reference to assembly 'netstandard, Version=2.0.0.0

Question

The project is an ASP.NET MVC Web App targeting the .NET Framework 4.6.1.

All of a sudden (some NuGet packages were upgraded) I started to get the following error du

Answer 1

I had to do a combination of other people's answers on this thread.

1. Install the NetStandard.Library via NuGet
2. Manually editing the .csproj file and adding the reference.
3. Expanding project-->References in the VS Solution Explorer, right clicking on 'netstandard' and showing the properties page and setting "Copy Local" to true.