Exception 0xE0434352 when creating a second window in UWP app with Template 10

I found this SO question, and also a relevant answer here, but I am still getting exceptions when I try to implement multiple windows using Template 10.

(I also found this SO question, which appears to recommend jumping out of Template 10 altogether, and using a Frame directly. When I tried the code in the answer, I got a CLR exception. So I abandoned that approach and went back to the other questions).

As far as I understand from the descriptions here and here, you need to create a new frame and navigation service, assign the navigation service to your frame, and then use the navigation service to navigate to the new page.

I tried this code in the ViewModel of the page navigated from, but it gets exception 0xE0434352 at the first line when creating the frame.

Frame secondaryFrame = new Frame();      //--->Exception 0xE0434352
var secondaryNav = BootStrapper.Current.NavigationServiceFactory(BootStrapper.BackButton.Attach, BootStrapper.ExistingContent.Exclude, secondaryFrame);
secondaryNav.Navigate(typeof(MySecondaryPage));
Window.Current.Content = secondaryFrame; //activation

Why does creating a Frame get an exception?
And is the above code correct for opening a secondary window?

EDIT: Thanks to mvermef's answer on this question, I have now found the UWP sample for multiple windows on GitHub. It is available in version 1.1.13p of the UWP samples, in /Samples/MultipleViews/ViewModels/, here.

My original attempt at opening a secondary window using NavigationService.OpenAsync() was the same as the corresponding line of code in the sample. This is the function:

        private async void MyEventHandler(bool openSecondaryWindow)
    {
        await DispatcherWrapper.Current().DispatchAsync(async () =>
        {
            if (openSecondaryWindow)
            {
                try
                {
                   //the next line gets exception 0xE0434352
                    var control = await NavigationService.OpenAsync(typeof(MySecondaryPage), null, Guid.NewGuid().ToString());  

                    control.Released += Control_Released;
                }
                catch (Exception ex)  
                {

                }
            }
        });
    }

It still gets exception 0xE0434352. I have tried it with my secondary page, with another page that usually opens without a problem, and with a blank page that I created. All attempts get the same exception.

As far as I understand from the descriptions here and here, you need to create a new frame and navigation service, assign the navigation service to your frame, and then use the navigation service to navigate to the new page.

You have different ways to implement this behavior with NavigationService OpenAsync method.

await NavigationService.OpenAsync(typeof(Views.TestPage));

You could also use ViewService OpenAsync method.

var viewservice = new ViewService();
await viewservice.OpenAsync(typeof(Views.TestPage));

Please make sure that it was invoked in the UI thread.