У меня есть следующий XAML:

<UserControl x:Class="EMS.Controls.Dictionary.TOCControl"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:vm="clr-namespace:EMS.Controls.Dictionary.Models"
    xmlns:diagnostics="clr-namespace:System.Diagnostics;assembly=WindowsBase"
    x:Name="root"  >

    <TreeView                    
        x:Name="TOCTreeView"                    
        Background="White"
         Padding="3,5"      
        ContextMenuOpening="TOCTreeView_ContextMenuOpening"
        ItemsSource="{Binding Children}" BorderBrush="{x:Null}"  >

        <TreeView.ItemTemplate>
            <HierarchicalDataTemplate ItemsSource="{Binding Path=Children, Mode=OneTime}">
                <Grid >
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto"/>
                        <!--<ColumnDefinition Width="Auto"/>-->                       
                        <ColumnDefinition Width="*"/>
                    </Grid.ColumnDefinitions>
                    <!--<CheckBox VerticalAlignment="Center" IsChecked="{Binding IsVisible}"/>-->   
                    <ContentPresenter Grid.Column="0" Height="16" Width="20"
                                    Content="{Binding LayerRepresentation}"  />
                    <!--<ContentPresenter Grid.Column="1"      >
                        <ContentPresenter.Content>
                            Test
                        </ContentPresenter.Content>
                    </ContentPresenter>-->
                    <TextBlock Grid.Column="2" FontWeight="Normal" Text="{Binding Path=Alias, Mode=OneWay}" >
                        <ToolTipService.ToolTip>
                            <TextBlock Text="{Binding Description}" TextWrapping="Wrap"/>
                        </ToolTipService.ToolTip>
                    </TextBlock>
                </Grid>
                <HierarchicalDataTemplate.ItemTemplate>
                    <HierarchicalDataTemplate ItemsSource="{Binding Path=Children, Mode=OneTime}">
                        <!--<DataTemplate>-->
                        <Grid >
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="Auto"/>
                                <ColumnDefinition Width="Auto"/>                               
                                <ColumnDefinition Width="*"/>
                            </Grid.ColumnDefinitions>
                            <CheckBox VerticalAlignment="Center" IsChecked="{Binding IsVisible}"/>
                            <ContentPresenter Grid.Column="1"
                                    Content="{Binding LayerRepresentation, Mode=OneWay}"  />
                            <TextBlock Margin="0,1,0,1" Text="{Binding Path=Alias, Mode=OneWay}" Grid.Column="2">
                                <ToolTipService.ToolTip>
                                    <TextBlock Text="{Binding Description}" TextWrapping="Wrap"/>
                                </ToolTipService.ToolTip>                   
                            </TextBlock>
                        </Grid>
                        <!--</DataTemplate>-->
                    </HierarchicalDataTemplate>                  
                </HierarchicalDataTemplate.ItemTemplate>
            </HierarchicalDataTemplate>
        </TreeView.ItemTemplate> 

        <TreeView.ContextMenu>
            <ContextMenu>
                <MenuItem Name="miRemove" Header="Remove"
                          Command="{Binding ElementName=root, Path=RemoveItemCmd, 
                    diagnostics:PresentationTraceSources.TraceLevel=High}">
                    <MenuItem.Icon>
                        <Image Source="../images/16x16/Delete.png"/>
                    </MenuItem.Icon>
                </MenuItem>
                <MenuItem Header="Properties"
                          Command="{Binding ElementName=root, Path=GetItemPropertiesCmd}"/>               
            </ContextMenu>       
        </TreeView.ContextMenu>


    </TreeView>

</UserControl>

Код для этого UserControl имеет два свойства ICommand с именами: RemoveItemCmd и GetItemPropertiesCmd. Тем не менее, я получаю

System.Windows.Data Error: 4 : Cannot find source for binding with reference 'ElementName=root'. BindingExpression:Path=RemoveItemCmd; DataItem=null; target element is 'MenuItem' (Name='miRemove'); target property is 'Command' (type 'ICommand')
System.Windows.Data Error: 4 : Cannot find source for binding with reference 'ElementName=root'. BindingExpression:Path=GetItemPropertiesCmd; DataItem=null; target element is 'MenuItem' (Name=''); target property is 'Command' (type 'ICommand')

когда UserControl построен. Почему это и как мне решить?