Tag helper Intellisense issue

Question

Tag helpers are not showing intellisense. Moreover, coloring of their attributes are not working either. What I may be missing? Following is my .cspro file. Note: My _ViewImports.cshtml view contains @addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

.csproj File

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

  <PropertyGroup>
    <TargetFramework>netcoreapp1.1</TargetFramework>
    <PreserveCompilationContext>true</PreserveCompilationContext>
    <AssemblyName>TestProj</AssemblyName>
    <OutputType>Exe</OutputType>
    <PackageId>TestProj</PackageId>
    <UserSecretsId>aspnet-TestProj-6af8ade3-87ff-4468-a9ce-8bb69c696ab8</UserSecretsId>
    <RuntimeFrameworkVersion>1.1.1</RuntimeFrameworkVersion>
    <PackageTargetFallback>$(PackageTargetFallback);dotnet5.6;portable-net45+win8</PackageTargetFallback>
  </PropertyGroup>

  <ItemGroup>
    <None Remove="Properties\PublishProfiles\TestProjP.pubxml" />
    <None Remove="Properties\PublishProfiles\FolderProfile.pubxml" />
    <None Remove="Properties\PublishProfiles\FolderProfile1.pubxml" />
  </ItemGroup>

  <ItemGroup>
    <None Update="wwwroot\**\*;Views\**\*;Areas\**\Views">
      <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory>
    </None>
  </ItemGroup>

  <ItemGroup>
    <PackageReference Include="bootstrap" Version="2.3.2" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="1.1.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="1.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="1.1.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer.Design" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Authentication.Cookies" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Diagnostics" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Identity" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Server.IISIntegration" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Server.IISIntegration.Tools" Version="1.1.0-preview4-final" />
    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="1.1.1" />
    <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="1.1.1" />
    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="1.1.1" />
    <PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="1.1.1" />
    <PackageReference Include="Microsoft.Extensions.Logging" Version="1.1.1" />
    <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="1.1.1" />
    <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="1.1.1" />
    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="1.1.1" />
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="1.1.0">
      <PrivateAssets>All</PrivateAssets>
    </PackageReference>
    <PackageReference Include="Microsoft.AspNetCore.Session" Version="1.1.1" />
    <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="1.1.1" />
    <PackageReference Include="Microsoft.VisualStudio.Web.BrowserLink" Version="1.1.0" />
    <PackageReference Include="BundlerMinifier.Core" Version="2.3.327" />
    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.2" />
    <PackageReference Include="Microsoft.AspNetCore.Mvc.Core" Version="1.1.2" />
    <PackageReference Include="EPPlus.Core" Version="1.4.0" />
  </ItemGroup>

 <ItemGroup>
    <DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="1.0.0" />
  </ItemGroup>

</Project>

Answer 1

Refer to this: https://github.com/aspnet/Razor/issues/1628, please re-run the VS 2017 installer as administrator and click ‘Update’ to upgrade to the VS 2017 15.3.3 version, I tried to create a new Asp.NET Core web application to test it, it works fine as below: