WinUI3 in Desktop template App crashes when activating two Windows in App.xaml.cs

[minesworld]

Describe the bug

VisualStudio 2022 tries to attach another debugger when App.xaml.cs tries to activate two Windows:

protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
{
    m_window = new MainWindow();
    m_window.Activate();

    m_window = new MainWindow();
    m_window.Activate();
}

Output:
The program '[26132] DebuggerCrash.exe' has exited with code 3221225477 (0xc0000005) 'Access violation'.

This happens (DebuggerCrash project) using

• Microsoft.WindowsAppSDK 1.4.231008000
• Microsoft.Windows.SDK.BuildTools 10.0.22621.756

This does not happen (DebuggerNoCrash project) using

• Microsoft.WindowsAppSDK 1.3.230602002
• Microsoft.Windows.SDK.BuildTools 10.0.22621.755

Both projects run without any issues if started WITHOUT debugging from VisualStudio 2022

Steps to reproduce the bug

1. download the AppSDKBugs repo from https://github.com/minesworld/AppSDKBugs
2. debug the DebuggerCrash project

Expected behavior

should open and continue debugging without any issues

Screenshots

No response

NuGet package version

WinUI 3 - Windows App SDK 1.4.2: 1.4.231008000

Windows version

Windows 11 (22H2): Build 22621

Additional context

No response

[DarranRowe]

Yes, this should be known and related to the In-App Toolbar.

As a workaround, you can disable the In-App Toolbar from the Live Visual Tree tool window in Visual Studio.

This only appears when Visual Studio is debugging a Xaml window.

[minesworld]

Thanks a lot. Spent hours on that. Seems that "should be known" didn't work in my case. Wonder if there could be solution within the generated XAML startup code to check if that option is on and WriteLine a statement....