MainWindow.xaml:

<Window.Resources>
        <local:DoubleRangeRule x:Key="DoubleRangeRule"/>
        <Style x:Key="textBoxInError" TargetType="{x:Type TextBox}">
            <Style.Triggers>
                <Trigger Property="Validation.HasError" Value="true">
                    <Setter Property="ToolTip"  Value="{Binding RelativeSource={x:Static RelativeSource.Self},  Path=(Validation.Errors)/ErrorContent}"/>
                </Trigger>
            </Style.Triggers>
        </Style>
        <ControlTemplate x:Key="validationTemplate">
            <DockPanel>
                <TextBlock Foreground="Red" FontSize="20">!</TextBlock>
                <AdornedElementPlaceholder/>
            </DockPanel>
        </ControlTemplate>
    </Window.Resources>
    <Grid Margin="0,0,0,-70">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="auto"/>
            <ColumnDefinition Width="auto"/>
            <ColumnDefinition Width="auto"/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto"/>
        </Grid.RowDefinitions>
        <Label x:Name="TrialName"   Height="40" VerticalAlignment="Top"   Content="Trial" FontFamily="Arial Black" FontWeight="Bold" FontSize="20" Margin="0,5,0,0" HorizontalAlignment="Left" 
                      Width="70" Grid.Column="1" Grid.Row="1" Background="OldLace" />

        <Separator/>
        <Label Grid.Column="1"  Content="Dice Threshold" HorizontalAlignment="Left" Margin="450,146,0,0" Grid.Row="1" VerticalAlignment="Top" 
                    Background="Wheat" FontFamily="Arial Black" FontWeight="Bold" FontSize="20" Width="185" Height="46"/>
        <TextBox x:Name="DiceTol" Grid.Column="1" HorizontalAlignment="Left"
                 Margin="655,146,0,0" Grid.Row="1"   Background="Wheat" Width="100" Height="46" 
                 Validation.ErrorTemplate="{StaticResource validationTemplate}"   
                 Style="{StaticResource textBoxInError}"
                   local:ProtocolSettingsLayout.MVVMHasError="{Binding Path=HasError}">
            <TextBox.Text>
                <Binding Path="DiceThreshold"  Mode="TwoWay"  StringFormat="N2"  UpdateSourceTrigger="PropertyChanged">
                    <Binding.ValidationRules>
                        <local:DoubleRangeRule Min="0.0" Max="1.0"/>
                    </Binding.ValidationRules>
                </Binding>
            </TextBox.Text>
        </TextBox>
        <TextBlock Grid.Column="1" Grid.Row="2"   Text="{Binding DiceThreshold ,Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="100" Height="40"/>
        <TextBlock Grid.Column="1" Grid.Row="3" x:Name="tb2"  Width="100" Height="40">
            <TextBlock.Text>
                <Binding Path="HasError" StringFormat="HasError is {0}"/>
            </TextBlock.Text>
        </TextBlock>
        <TextBlock Grid.Column="1" Grid.Row="4">
            <TextBlock.Text>
                <Binding Path="(Validation.HasError)" ElementName="DiceTol" StringFormat="Validation.HasError is {0}"/>
            </TextBlock.Text>
        </TextBlock>
        <Button Grid.Column="1" Grid.Row="5"  x:Name="AutoMatchedStruct"  IsEnabled="{Binding IsValidObject}" Content="Load Matched Structures" Width="180" Height="40" Click="Button_Click"/>
    </Grid>