Microsoft.Aspnetcore.Authorization namespace is missing with .NET Core 2.2

Microsoft.Aspnetcore.Authorization namespace is missing when using .NET Core 2.2

To Reproduce

1. Set TargetFramework of .csproj file to “netcoreapp2.2”
2. Set RuntimeFrameworkVersion to “2.2.0”
3. Include PackageReference “Microsoft.AspNetCore.App”
4. Try to use Authorize attribute or to Microsoft.AspNetCore.Authorization namespace in any controller.
5. Namespace is not found.

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>netcoreapp2.2</TargetFramework>
    <RuntimeFrameworkVersion>2.2.0</RuntimeFrameworkVersion>
    <DebugType>Full</DebugType>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.App"/>
  </ItemGroup>
</Project>

Expected behavior Running the same project with net core 2.1 works fine. Tried to include Microsoft.AspNetCore.Authorization package explicitly using nuget with no success. Error appears to be the same.

Screenshots

Desktop:

• OS: Windows 10 x64
• IDE: Visual Studio 15.9.3

[jonnale]

I just had this same exact issue pop-up again, but this time with the Microsoft.AspNetCore.Authentication.Cookies package.

I installed this package to my project using Install-Package Microsoft.AspNetCore.Authentication.Cookies -Version 2.2.0. After doing that, I still could not reference it in my project. When I highlighted the dependency in my project and looked at the properties, I saw the Path for that package was set to C:\Program Files\dotnet\sdk\NuGetFallbackFolder\microsoft.aspnetcore.authentication.cookies\2.2.0

I went in and removed the entire folder C:\Program Files\dotnet\sdk\NuGetFallbackFolder\microsoft.aspnetcore.authentication.cookies and then did a package restore in VS. After doing this, I noticed it updated the Path to C:\Users\<my user name>\.nuget\packages\microsoft.aspnetcore.authentication.cookies\2.2.0.

I then rebuilt the project and everything worked. I can now reference Microsoft.AspNetCore.Authentication.Cookies.

I would not be surprised if this was the same issue.

[Eilon]

Thanks for the extra info @jonnale . It’s not clear to us the exact cause for this but if anyone has exact steps to reproduce this problem, please upload your project to a GitHub repo with instructions on what to install, what to run, etc., and we can try to investigate more. In the meantime I’m closing this issue because there’s no immediate action for us to take here.