UnhandledException for NumberBox SpinButtonPlacementMode.Compact when opening in a window twice in WinAppSDK >= 1.6.240829007

[TRadigk]

Describe the bug

Hi,
there is a very easy to run reproduction repository for this issue:
https://github.com/TRadigk/NumberBoxCrashRepro

Please see the provided steps to reproduce the bug.

Packaged/NonPackaged makes no difference. The issue is found in 1.6.240829007 and newer, not present in earlier versions.

Unfortunately I am not able to debug any further than "invalid parameter" being found in the unhandled exception, which is not helpful.

Steps to reproduce the bug

1. Clone the repository.
2. Open the solution in Visual Studio.
3. Build the solution.
4. Run the application.
5. Click the "Click Me" button on first window.
6. Click the number zone in the NumberBox in the new window (so that the flyout with the spin buttons is shown at least once)
7. Close the secondary window
8. Click the "Clicked" button on first window.

Expected behavior

App behaves the same with Inline or Hidden setting.
or
App behaves the same as with using WinAppSDK 1.5.250108004.

Screenshots

No response

NuGet package version

WinUI 3 - Windows App SDK 1.7.0: 1.7.250310001

Windows version

No response

Additional context

No response

[ayushjai30]

Hi @TRadigk, I am not able to repro the issue with your given repo. Can you please check again?

[TRadigk]

Hi @ayushjai30 ,

I've tried the repro myself. And also inside the original app, where I had a comment about using "inline" for the moment, where "compact" leads to the described crash. I also tried to copy over the repro to Windows Sandbox but in neither scenarios I was able to reproduce the crash.
I must conclude that Windows Updates within the last three months must have had impact on this in a positive way.

I close the issue and thank you very much for your response!