.NET Core 3 Invalid reference from Common Library - .net-core

Question

I need 2 assemblies for my .NET Core 3 WPF App - System.Windows.Forms and System.Drawing.Common.
When I try to add them as references in Visual Studio 2019 from the common shared folder (C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App\3.0.0) i get an exception message box saying "The reference is invalid or unsupported".
I would expect this kind of thing to happen with framework mismatches, but this is from the dotnet core v3 shared folder, so everything should line up.
Is there any particular trick to adding these references that I am unaware of?
csproj file:
<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
<PropertyGroup>
<OutputType>WinExe</OutputType>
<TargetFramework>netcoreapp3.0</TargetFramework>
<UseWPF>true</UseWPF>
<UseWindowsForms>true</UseWindowsForms>
</PropertyGroup>
<ItemGroup>
<ProjectReference Include="..\Common\Common.csproj" />
<ProjectReference Include="..\Core\Core.csproj" />
</ItemGroup>
<ItemGroup>
<None Update="logo.ico">
<CopyToOutputDirectory>Always</CopyToOutputDirectory>
</None>
</ItemGroup>
</Project>

Answer 1

In the .NET Core, the project system does not handle well binary assembly references. It may not always work and is an unsupported and unrecommended way to reference assemblies. The proper way is to use package references or framework references. The latter are expressed at the top level of the project via the Sdk attribute i.e. <Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">.
First of all, you should not add assembly references but add package references either manually or using the package manager. The reference to System.Drawing.Common assembly for .NET Core 3.0 target should look as follows:
<PackageReference Include="System.Drawing.Common" Version="4.6.0" />