W10 IOT cannot install Microsoft.NETCore.UniversalWindowsPlatform

I developed a background application for Windows 10 Iot to run on a Raspberry Pi but when I create the new project I get the following Error:

If I manually add the last version of Microsoft.NETCore.UniversalWindowsPlatform package and than I start Build I get a lots of errors.

The temporary fix that works for me is the following :

• replace in your .csproj file

<ItemGroup>
  <!-- A reference to the entire .Net Framework and Windows SDK are automatically included -->
  <None Include="project.json" />
</ItemGroup>

with

<PropertyGroup>
  <RestoreProjectStyle>PackageReference</RestoreProjectStyle>
</PropertyGroup>

• and after manually add the Microsoft.NETCore.UniversalWindowsPlatform package from nuget manager

And finally I can Build my app.