Использование проверки данных в ControlTemplate

Пытаюсь сформировать проверку данных в Wpf. Примеры из нета работают. Но когда хочу переместить все шаблон не визуально не показывает ошибку. Код модели:

public class Model: INotifyPropertyChanged, IDataErrorInfo
{
    #region Members
    private string _name;
    public string Name {
        get { return _name; }
        set { _name = value; this.SendPropertyChanged("Name"); }
    }
    private int _index;
    public int Index {
        get { return _index; }
        set { _index = value; this.SendPropertyChanged("Index"); }
    }
    #endregion
    #region Members IDataErrorInfo
    private Dictionary<string, string> _errors = new Dictionary<string, string>();
    public string Error
    {
        get { return string.Join<string>(Environment.NewLine, _errors.Select(x => x.Value)); }
    }
    public string this[string columnName]
    {
        get
        {
            string error = string.Empty;
            switch (columnName)
            {
                case "Name":
                    if (Name == null || Name.Length == 0)
                        error = _errors["Name"] = "value by not emprty";
                    else
                        _errors.Remove("Name");
                    break;
                case "Index":
                    if (Index == 0)
                        error = _errors["Index"] = "Index by less zero";
                    else
                        _errors.Remove("Index");
                    break;
            }
            return error;
        }
    } 
    #endregion
    #region Members INotifyPropertyChanged
    public event PropertyChangedEventHandler PropertyChanged;
    protected void SendPropertyChanged(string propertyName = "") {
        if (PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
    }
    #endregion
}

Разметка в App:

    <Application.Resources>
    <ResourceDictionary>
        <ControlTemplate x:Key="winTemplate" TargetType="{x:Type Window}">
            <Grid Background="{TemplateBinding Background}">
                <Grid.RowDefinitions>
                    <RowDefinition Height="50" />
                    <RowDefinition Height="50" />
                    <RowDefinition Height="50" />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="10" />
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>
                <PasswordBox Grid.Column="1" Grid.Row="1" VerticalAlignment="Center" Margin="20, 0" >
                    <b:PasswordBoxBehaviour.Password>
                        <Binding Path="Name" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged" ValidatesOnDataErrors="True">
                            <Binding.ValidationRules>
                                <DataErrorValidationRule />
                            </Binding.ValidationRules>
                        </Binding>
                    </b:PasswordBoxBehaviour.Password>
                </PasswordBox>
                <TextBox Grid.Column="1" Grid.Row="2" VerticalAlignment="Center" Margin="20, 0" >
                    <TextBox.Text>
                        <Binding Path="Index" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged" ValidatesOnDataErrors="True">
                            <Binding.ValidationRules>
                                <DataErrorValidationRule ValidatesOnTargetUpdated="True" />
                            </Binding.ValidationRules>
                        </Binding>
                    </TextBox.Text>
                </TextBox>
            </Grid>
        </ControlTemplate>
    </ResourceDictionary>
</Application.Resources>

В итоге не отображаются ошибки:

Подскажите в чем может быть проблема.