UWP references fail when setting TargetPlatformMinVersion

[Morten Nielsen]

Create a multi-targeted project like this:

<Project Sdk="MSBuild.Sdk.Extras/3.0.44">
  <PropertyGroup>
    <TargetFrameworks>netstandard2.0;uap10.0.19041</TargetFrameworks>
    <TargetPlatformMinVersion Condition="'$(TargetFramework)'=='uap10.0.10941'">10.0.17763.0</TargetPlatformMinVersion>
  </PropertyGroup>
</Project>

Next create a second project that references this:

<Project Sdk="MSBuild.Sdk.Extras/3.0.44">
  <PropertyGroup>
    <TargetFramework>uap10.0.19041</TargetFramework>
    <TargetPlatformMinVersion>10.0.17763.0</TargetPlatformMinVersion> <!-- Remove and problem gone -->
  </PropertyGroup>
  <ItemGroup>
    <ProjectReference Include="..\Common\Common.csproj"  />
  </ItemGroup>
</Project>

This causes the build error

2>E:\sources.tmp\BuildRepro\Common\Common.csproj : error MSB4057: The target "GetTargetPath" does not exist in the project.
2>Done building project "Common.csproj" -- FAILED.

If you remove TargetPlatformMinVersion or set it to 19041 on the second project, the problem goes away.

If you replace the second project with a classic UWP class library project, there is no issue.

[Morten Nielsen]

Found a workaround: In the second project pluralize TFM so it says TargetFrameworks and problem goes away 🤦