Why can't I install Microsoft.VisualStudio.Web.CodeGeneration.Tools 2.0.1 via nuget? Asp.NET CORE 2.0.1 - asp.net

Question

I have added the reference to my project.csproj file as indicated on S.O. and in the ms docs tutorial:
<ItemGroup>
<DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="2.0.1" />
</ItemGroup>
running dotnet restore claims to succeed. But the dotnet aspnet-codegenerator command can't be found and in the manage nuget packages, the CodeGeneration.Tools isn't installed and manually installing gives the error:
Package restore failed. Rolling back package changes for 'ContosoUniversity'.
This appears to be from a version compatibility issue that I don't understand or know how to fix. I have installed in my dependencies Microsoft.NETCore.App 2.0.3
and Microsoft.NETCore.APP 2.0.3 and everything else is 2.0.1. (CodeGeneration.Design, CodeGeneration.Utils etc... and running at Package Management Console Install-Package Microsoft.VisualStudio.Web.CodeGeneration.Tools Throws the error:
GET https://api.nuget.org/v3/registration3-gz-semver2/microsoft.visualstudio.web.codegeneration.tools/index.json
OK https://api.nuget.org/v3/registration3-gz-semver2/microsoft.visualstudio.web.codegeneration.tools/index.json 166ms
Restoring packages for C:\Users\sticker592\Documents\Visual Studio 2017\Projects\ContosoUniversity\ContosoUniversity\ContosoUniversity.csproj...
Install-Package : Detected package downgrade: Microsoft.NETCore.App from 2.0.3 to 2.0.0. Reference the package directly from the project to
select a different version.
ContosoUniversity -> Microsoft.VisualStudio.Web.CodeGeneration.Tools 2.0.1 -> Microsoft.NETCore.App (>= 2.0.3)
ContosoUniversity -> Microsoft.NETCore.App (>= 2.0.0)
At line:1 char:1
+ Install-Package Microsoft.VisualStudio.Web.CodeGeneration.Tools
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Install-Package], Exception
+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PackageManagement.PowerShellCmdlets.InstallPackageCommand
Install-Package : Package restore failed. Rolling back package changes for 'ContosoUniversity'.
At line:1 char:1
+ Install-Package Microsoft.VisualStudio.Web.CodeGeneration.Tools
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Install-Package], Exception
+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PackageManagement.PowerShellCmdlets.InstallPackageCommand
Downgrading everything to 2.0.0 allows me to install CodeGeneration.Tools in Nuget but I still get the error: dotnet : No executable found matching command "dotnet-aspnet-codegenerator"

Answer 1

Go to "Manage Nuget Package for solution" in Nuget Package Manager and
In Package Source
.
Add below detail:
Name
"nuget.org"
source
"https://api.nuget.org/v3/index.json"

Answer 2

If this happens, the solution to the error is to run the command at the dos command prompt in the project folder directory instead of in Package manager console. Then you can scaffold your pages without the error until MS fixes this bug.
Proof:
C:\Users\username\Documents\Visual Studio 2017\Projects\ContosoUniversity\ContosoUniversity>dotnet aspnet-codegenerator razorpage -m Student -dc SchoolContext -udl -outDir Pages\Students --referenceScriptLibraries
Building project ...
Finding the generator 'razorpage'...
Running the generator 'razorpage'...
Attempting to compile the application in memory.
Attempting to figure out the EntityFramework metadata for the model and DbContext: 'Student'
info: Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[0]
User profile is available. Using 'C:\Users\username\AppData\Local\ASP.NET\DataProtection-Keys' as key repository and Windows DPAPI to encrypt keys at rest.
info: Microsoft.EntityFrameworkCore.Infrastructure[100403]
Entity Framework Core 2.0.0-rtm-26452 initialized 'SchoolContext' using provider 'Microsoft.EntityFrameworkCore.SqlServer' with options: None
Added Razor Page : \Pages\Students\Create.cshtml
Added PageModel : \Pages\Students\Create.cshtml.cs
Added Razor Page : \Pages\Students\Edit.cshtml
Added PageModel : \Pages\Students\Edit.cshtml.cs
Added Razor Page : \Pages\Students\Details.cshtml
Added PageModel : \Pages\Students\Details.cshtml.cs
Added Razor Page : \Pages\Students\Delete.cshtml
Added PageModel : \Pages\Students\Delete.cshtml.cs
Added Razor Page : \Pages\Students\Index.cshtml
Added PageModel : \Pages\Students\Index.cshtml.cs
RunTime 00:00:15.33