Our app suddenly fails to show toast notifications

[reiseder]

Our app suddenly throws an UnauthorizedAccessException when trying to show a basic toast notification.

It worked fine until a few days ago, so my question would be if this was cause by a Windows update or just our IT department changing something?

The app runs with elevated rights.

It would be great if anybody knows what this registry key is used for?

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Exception message:

Failed initializing notifications

Stack trace:

   at Microsoft.Toolkit.Uwp.Notifications.ToastNotificationManagerCompat.CreateToastNotifier()
   at Microsoft.Toolkit.Uwp.Notifications.ToastContentBuilder.Show(CustomizeToast customize)
   at Microsoft.Toolkit.Uwp.Notifications.ToastContentBuilder.Show()
   at <REDACTED METHOD> in <REDACTE FILE>:line 200
   at <REDACTED METHOD> in <REDACTE FILE>:line 172
   at System.Windows.Threading.DispatcherOperation.InvokeDelegateCore()
   at System.Windows.Threading.DispatcherOperation.InvokeImpl()

Inner exception message:

Access to the registry key 'HKEY_CURRENT_USER\SOFTWARE\Classes\CLSID\{5a99e422-303c-ea88-3583-506ae78a9819}\LocalServer32' is denied.

Inner exception stack trace:

   at Microsoft.Win32.RegistryKey.Win32Error(Int32 errorCode, String str)
   at Microsoft.Win32.RegistryKey.CreateSubKey(String subkey, RegistryKeyPermissionCheck permissionCheck, RegistryOptions registryOptions)
   at Microsoft.Toolkit.Uwp.Notifications.ToastNotificationManagerCompat.RegisterComServer(Type activatorType, String exePath)
   at Microsoft.Toolkit.Uwp.Notifications.ToastNotificationManagerCompat.RegisterActivator(Type activatorType)
   at Microsoft.Toolkit.Uwp.Notifications.ToastNotificationManagerCompat.CreateAndRegisterActivator()
   at Microsoft.Toolkit.Uwp.Notifications.ToastNotificationManagerCompat.Initialize()
   at Microsoft.Toolkit.Uwp.Notifications.ToastNotificationManagerCompat..cctor()

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This is how we show the toast notification

private void ShowMessage(string message)
{
    new ToastContentBuilder()
        .AddArgument("action", "viewConversation")
        .AddArgument("conversationId", SomeIdProperty)
        .AddText(SomeProductNameProperty)
        .AddText(message)
        .Show();
}