Unable to add API Controller in Visual Studio 2019. Unable to run the selected Code generator, package restore failed

I am using Visual Studio Community Edition 2019 ver 16.9.4 and .net core v3.1.14. Trying to scaffold an API Controller with CRUD operations. Get an error that says "Unable to run the selected code generator. Package restore failed. Rolling back package changes for ' I checked the Nuget package sources. Have already added the EntityFrameworkCore.SqlServer, EntityFrameworkCore and EntityFrameworkCore.Design Nuget packages. Below screen grab captures the vital details of the issue...

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.14" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="3.1.14">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="3.1.14" />
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="3.1.5" />
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\PluralSight.Core\PluralSight.Core.csproj" />
    <ProjectReference Include="..\Pluralsight.Data\Pluralsight.Data.csproj" />
  </ItemGroup>

  <ItemGroup>
    <Folder Include="Api\" />
  </ItemGroup>

</Project>