Default WinUI3 c# solution does not run

[ScottAlexanderOpto]

Describe the bug

Just updated VS2022 to version 17.12.5
Created a brand new WinUI3 C# application.
Tried to run it (previous version worked ... had a button to be clicked in the UI).
This version has all compile errors. No reference to Microsoft.UI.Xaml. Installed it using NuGet.
Now get error:
Cannot create instance of type 'Microsoft.UI.Xaml.Controls.XamlControlsResources' [Line: 10 Position: 40]

Steps to reproduce the bug

1. File::New::Project
2. In Create a new project window, select "Blank App, Packaged (WinUI 3 in Desktop) ... and give it a name
3. Build::Rebuild Solution
4. Debug::Start Debugging

Expected behavior

Should load the app with a button in the center of the screen. Clicking the button changes the content to "Clicked".

Screenshots

No response

NuGet package version

None

Windows version

Windows 11 (24H2): Build 26100

Additional context

No response

[whiskhub]

There is no "Microsoft.UI.Xaml" NuGet package. The required package is called Microsoft.WindowsAppSdk.

Try creating a clean project again, and compile it once. Maybe there are errors in the editor before the first compile.

[ScottAlexanderOpto]

hmmm ... well, I have this ... the installed NuGet packages shown in VS

and I get this error upon starting the app:
#if DEBUG && !DISABLE_XAML_GENERATED_BREAK_ON_UNHANDLED_EXCEPTION
UnhandledException += (sender, e) =>
{
if (global::System.Diagnostics.Debugger.IsAttached) global::System.Diagnostics.Debugger.Break();
};
Exception thrown: 'System.Runtime.InteropServices.COMException' in WinRT.Runtime.dll
WinRT information: The application called an interface that was marshalled for a different thread.

Not much of a template, certainly not what I'm used to getting.

[whiskhub]

Uninstall that Microsoft.Ui.Xaml package. This is for UWP apps and causing the incompatibility.

[ScottAlexanderOpto]

I will; but, I also see it in the MediaCaptureWinUI sample project ... fyi ... so lots of confusion.