ListBoxItem produces “System.Windows.Data Error: 4” binding error

The easiest way to solve this is to ensure that your Listbox has a ItemContainerStyle. See the following example:

<ListBox x:Name="RecentItemsListBox" Grid.Row="1" BorderThickness="0" Margin="2,0,0,0" SelectionChanged="RecentItemsListBox_SelectionChanged">
    <ListBox.ItemContainerStyle>
        <Style TargetType="{x:Type ListBoxItem}">
            <Setter Property="HorizontalContentAlignment" Value="Left"/>
            <Setter Property="VerticalContentAlignment" Value="Center"/>
        </Style>
    </ListBox.ItemContainerStyle>

...

</ListBox>

What happens is that your Items are being created, and by default they look for parent’s property which isn’t defined. Explicitly defining it will solve this problem.

I had the same issue using a TreeView and changing the bound source for these templates would cause those warnings.