Replace this:
<button horizontalalignment="Right" height="30" width="80" content="Logout" margin="5" click="Logout_Button_Click" />
<navigation:frame grid.row="1" x:name="nvContainer" horizontalalignment="Stretch" removed="#656D78" width="Auto" xmlns:x="#unknown" xmlns:navigation="#unknown" />
With this:
<stackpanel grid.row="1">
<Button HorizontalAlignment="Right" Height="30" Width="80" Content="Logout" Margin="5" Click="Logout_Button_Click" />
<navigation:frame x:name="nvContainer" horizontalalignment="Stretch" removed="#656D78" width="Auto" xmlns:x="#unknown" xmlns:navigation="#unknown" />
</stackpanel>
And it should work...