Max Katz

@General-Ridley same exception can't possibly happen if virtualization is disabled. Do you have different stacktrace? Or maybe steps to reproduce are different? To disable virtualization you need to change VirtualizationMode...

```csharp private sealed class Win32EmbedWindowImpl : Avalonia.Win32.WindowImpl ``` I don't think we want to keep WindowImpl a not internal class. @jp2masa hit testing is processed by renderer, yes. In case...

Same issue https://github.com/AvaloniaUI/Avalonia/issues/9218 https://github.com/AvaloniaUI/Avalonia/issues/8100 https://github.com/AvaloniaUI/Avalonia/issues/5762 https://github.com/AvaloniaUI/Avalonia/issues/5163

@rabbitism correct, expected behavior would be to throw an exception. And it is done with that PR https://github.com/AvaloniaUI/Avalonia/pull/8600

Please, update issue with more detailed description and add steps to reproduce or even better a minimal project where it can be reproduced.

@duxunmi can you attach an archive with project that can be reproduced? I tried your XAML code, and it works as expected: 

4189.2833ms is still sounds very wrong. Not sure if it's platform specific, but on m1 and intel windows I never had so bad numbers even on slower laptop. With r2r...

WindowNotificationManager can't be used immediately after object created. It needs to wait until its template will be applied. Also I don't see any reason to create new WindowNotificationManager per each...

However I think error message can be better in that case. FYI @danwalmsley

As I said you can't use WindowNotificationManager right after it was created. You either need to split this code as I described above, or you can subscribe TemplateApplied in which...