DateTime picker doesn't support error template

        [Editor(typeof(DatePropertyEditor), typeof(PropertyEditor))]
        public object FieldMinDT
        {
            get
            {
                return FieldMin;
            }

            set
            {
                                if (value == null) throw new Exception("test");
                FieldMin = value;
            }
        }

    public class DatePropertyEditor : PropertyEditor
    {
        #region Constructors

        public DatePropertyEditor()
        {
        }

        #endregion

        #region Overrides

        public override DataTemplate ValueTemplate
        {
            get;
            set;
        }

        public override object ValueTemplateKey
        {
            get
            {
                return "DatePropertyEditor";
            }
        }

        public override DataTemplateSelector ValueTemplateSelector
        {
            get;
            set;
        }

        #endregion
    }

    <DataTemplate x:Key="DatePropertyEditor">

        <shared:DateTimePicker Margin="0" IsEditable="True" BorderThickness="0" Value="{Binding Value, RelativeSource={RelativeSource AncestorType={x:Type propgrid:IPropertyDataAccessor}}, Mode=TwoWay}"
                               ValueConverterParameter="{x:Static shared:DateTimeToStringPattern.ShortDate}" />

    </DataTemplate>