[WinUI 3] Cannot locate resource from 'ms-appx:///FooLibrary/Themes/Foo.xaml'. [Line: X Position: Y]

[djonasdev]

Describe the bug

I have a source library HtSuite.WinUI.UI which is deployed as a nuget package. Inside of this project are some ResourceDictionary.
Now I made a new project, added my nuget package and wanted to link the ResourceDictionary in the App.xaml.

Steps to reproduce the bug

1. Create a Library project, add a ResourceDictionary and deploy it as a nuget package
2. Create a new WinUI project, add the nuget package and try to add the ResourceDictionary in the App.xaml

Expected behavior

No response

Screenshots

NuGet Package Project: HtSuite.WinUI.UI *.csproj

  <PropertyGroup>
    <TargetFramework>net6.0-windows10.0.18362.0</TargetFramework>
    <TargetPlatformMinVersion>10.0.18362.0</TargetPlatformMinVersion>
    <RootNamespace>Haprotec.WinUI.UI</RootNamespace>
    <RuntimeIdentifiers>win10-x86;win10-x64;win10-arm64</RuntimeIdentifiers>
    <UseWinUI>true</UseWinUI>
    <WindowsPackageType>None</WindowsPackageType>
    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
    <!--https://github.com/dotnet/maui/issues/5886-->
    <WinUISDKReferences>false</WinUISDKReferences>
    <EnablePreviewMsixTooling>true</EnablePreviewMsixTooling>
    <GenerateLibraryLayout>true</GenerateLibraryLayout>
    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
  </PropertyGroup>

CorporateDesign.xaml

T2020.UI Application with error message

NuGet package version

No response

Windows app type

• UWP
• Win32

Device form factor

No response

Windows version

No response

Additional context

No response

[djonasdev]

After I commented out the following flags, it now works as usual.
Among other things, these were leftovers from the beginnings of WinUI and were "forgotten" in the course of development or seem to highlight such problems.

  <PropertyGroup>
    <TargetFramework>net6.0-windows10.0.18362.0</TargetFramework>
    <TargetPlatformMinVersion>10.0.18362.0</TargetPlatformMinVersion>
    <RootNamespace>Haprotec.WinUI.UI</RootNamespace>
    <RuntimeIdentifiers>win10-x86;win10-x64;win10-arm64</RuntimeIdentifiers>
    <UseWinUI>true</UseWinUI>
    <!--<WindowsPackageType>None</WindowsPackageType>-->
    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
    <!--https://github.com/dotnet/maui/issues/5886-->
    <!--<WinUISDKReferences>false</WinUISDKReferences>-->
    <!--<EnablePreviewMsixTooling>true</EnablePreviewMsixTooling>-->
    <!--<GenerateLibraryLayout>true</GenerateLibraryLayout>-->
    <!--<AllowUnsafeBlocks>true</AllowUnsafeBlocks>-->
  </PropertyGroup>