Enable in-app Toolbar in XAML Hot Reload crashes in App SDK 1.5

[JochemPalmsens]

Describe the bug

This is a kind-of successor to #8806 I managed to get a situation where the application crashes when the XAML Hot Reload in-app toolbar is enabled, but now in WinAppSDK 1.5.240627000

Steps to reproduce the bug

I haven't pin-pointed it precisely, but it seems to happen when a new window (in our case containing a webview 2 element) is quickly opened and closed. (We use it for OAuth0 logout)

Expected behavior

Of course we expect the application not to crash. We have no issues when we disable the in-app toolbar

Screenshots

Exception:

Call stack:

NuGet package version

WinUI 3 - Windows App SDK 1.5.5: 1.5.240627000

Windows version

Windows 11 (22H2): Build 22621

Additional context

Visual Studio Professional 17.10.5

I would be glad to help debug this, but I don't know where to begin. The screenshot shows a null-reference exception

[github-actions[bot]]

Hi I'm an AI powered bot that finds similar issues based off the issue title.

Please view the issues below to see if they solve your problem, and if the issue describes your problem please consider closing this one. Thank you!

Closed similar issues:

• Enable in-app Toolbar in XAML Hot Reload crashes in App SDK 1.4 (#8806), similarity score: 0.85

Note: You can give me feedback by thumbs upping or thumbs downing this comment.

[JochemPalmsens]

I managed to get some disassebly info:

[wbokkers]

I see the same issue in App SDK 1.6 when closing a (child) Window.