Referencing C#/WinRT NuGet package from C# UWP apps gives MSBuildProjectExtensionsPath compile error

[Psychlist1972]

Trying to reference a local C#/WinRT nuget package from a C#/UWP app.

Error: Severity Code Description Project File Line Suppression State Error The MSBuildProjectExtensionsPath MSBuild property could not be found for project 'D:\peteb\Documents\GitHub\microsoft\midi\get-started\samples\csharp-uwp\VerifyServiceIsRunningCsUwp'.

This same NuGet package was able to be referenced from C++/WinRT once I fixed the targets names there (see my previous bug). Not sure if this is related.

This error makes it impossible to load the project.

[AdamBraden]

This is unsupported. You cannot mix net5 and uwp netnative.

@j0shuams - is there a better error message we can provide?