Microsoft.AspNet.Razor 3.2.3 is not compatible with netcoreapp1.1

Hello

When I use VS Community 2017 and try and install some new dependencies via NuGet Package manager (specifically, Razor tools, Static file and MVC) I get the following error:

 Package Microsoft.AspNet.Razor 3.2.3 is not compatible with netcoreapp1.1 (.NETCoreApp,Version=v1.1). Package Microsoft.AspNet.Razor 3.2.3 supports: net45 (.NETFramework,Version=v4.5)
One or more packages are incompatible with .NETCoreApp,Version=v1.1.

I've clicked on the cog next to the package source and clicked the update button (so I have the most resent package list).

I'm trying to load these files as I am following an online course, and the next step is to load Microsoft.AspNetCore.Razor.Tools , Microsoft.AspNetCore.StaticFiles and Microsoft.AspNetCore.Mvc ( the video instructor is using a lesser version that 2017.. so is that the problem ?).

The tutor goes on to talk about editing the project.json file ( which is now superseded by the csproj file ) to load them...

can anyone help shed some light for me ?

thanks in advance