Cannot instantiate a Page or User Control w/ NavigationView from a WinUI Class Library

[nikolayvpavlov]

Description

I have a WinUI 3 Class Library containing a page. I try to load these two in a grid in a separate WinUI 3 application. If the page contains a NavigationView object, the constructor of the page crashes with:

Microsoft.UI.Xaml.Markup.XamlParseException: 'XAML parsing failed.'

If the page contain something else, for example, a list box, it is loaded without any problems.

Sample Code

Loading the page

var c = new MyWinUILibrary.MyFabulousPage();
gridHost.Children.Add(c);

This works

<Page
    x:Class="MyWinUILibrary.MyFabulousPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:MyWinUILibrary"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

    <Grid>
        <ListBox Width="200">
            <x:String>Blue</x:String>
            <x:String>Green</x:String>
            <x:String>Red</x:String>
            <x:String>Yellow</x:String>
        </ListBox>
    </Grid>
</Page>

This doesn't:

<Page
    x:Class="MyWinUILibrary.MyFabulousPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:MyWinUILibrary"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

    <Grid>
        <NavigationView x:Name="navigationView" IsSettingsVisible="True">
            <NavigationView.MenuItems>
                <NavigationViewItem Icon="NewFolder" Content="Menu item 1" />
            </NavigationView.MenuItems>
            <Frame x:Name="frameContent" />
        </NavigationView>
    </Grid>
</Page>

Notes

I have tried with both a user control instead of a page and observed the same behavior. Using a NavigationView causes the constructor to crash.

If I embed the NavigationView in Xaml, all works properly.