After asking Designer/Blend to create a Copy of the Existing default Template for the PropertyGrid control, the UI is broken. The Template looks correct but no longer functions at Design-Time or Run-Time.
Before:

After specifying a Style:

Here is the Template Blend is Generating when specifying Edit Template > Edit a Copy...
```<Style x:Key="PropertyGridStyleDark" TargetType="{x:Type xctk:PropertyGrid}">
<Setter Property="AdvancedOptionsMenu">
<Setter.Value>
<ContextMenu>
<MenuItem Header="Reset Value">
<MenuItem.Command>
<RoutedCommand />
</MenuItem.Command>
</MenuItem>
</ContextMenu>
</Setter.Value>
</Setter>
<Setter Property="Background" Value="{DynamicResource {ComponentResourceKey ResourceId=ButtonNormalBackgroundKey, TypeInTargetAssembly={x:Type Themes:ResourceKeys}}}" />
<Setter Property="BorderBrush" Value="{DynamicResource {ComponentResourceKey ResourceId=ControlNormalBorderKey, TypeInTargetAssembly={x:Type Themes:ResourceKeys}}}" />
<Setter Property="BorderThickness" Value="1" />
<Setter Property="SelectedObjectType">
<Setter.Value>
<Binding
ConverterParameter="Type"
Path="SelectedObject"
RelativeSource="{RelativeSource Self}">
<Binding.Converter>
<xctk:SelectedObjectConverter />
</Binding.Converter>
</Binding>
</Setter.Value>
</Setter>
<Setter Property="SelectedObjectTypeName">
<Setter.Value>
<Binding
ConverterParameter="TypeName"
Path="SelectedObject"
RelativeSource="{RelativeSource Self}">
<Binding.Converter>
<xctk:SelectedObjectConverter />
</Binding.Converter>
</Binding>
</Setter.Value>
</Setter>
<Setter Property="SelectedObjectName">
<Setter.Value>
<Binding
ConverterParameter="SelectedObjectName"
Path="SelectedObject"
RelativeSource="{RelativeSource Self}">
<Binding.Converter>
<xctk:SelectedObjectConverter />
</Binding.Converter>
</Binding>
</Setter.Value>
</Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type xctk:PropertyGrid}">
<Border
Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}">
<Grid Margin="{TemplateBinding Padding}">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition />
<RowDefinition Height="5" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<StackPanel x:Name="selectObjectNamePanel" Orientation="Horizontal">
<Border
Width="44"
Height="44"
Margin="6,4,0,4"
Padding="2"
Background="White"
BorderBrush="Black"
BorderThickness="1">
<Border.Visibility>
<Binding Path="ShowPreview" RelativeSource="{RelativeSource TemplatedParent}">
<Binding.Converter>
<BooleanToVisibilityConverter />
</Binding.Converter>
</Binding>
</Border.Visibility>
<Rectangle>
<Rectangle.Fill>
<VisualBrush Stretch="Uniform">
<VisualBrush.Visual>
<Binding Path="SelectedObject" RelativeSource="{RelativeSource TemplatedParent}">
<Binding.Converter>
<xctk:ObjectToUIElementConverter />
</Binding.Converter>
</Binding>
</VisualBrush.Visual>
</VisualBrush>
</Rectangle.Fill>
</Rectangle>
</Border>
<StackPanel
Margin="6,2,6,4"
VerticalAlignment="Center"
Orientation="Horizontal">
<StackPanel.Visibility>
<Binding Path="ShowTitle" RelativeSource="{RelativeSource TemplatedParent}">
<Binding.Converter>
<BooleanToVisibilityConverter />
</Binding.Converter>
</Binding>
</StackPanel.Visibility>
<Grid>
<Grid.MaxWidth>
<Binding
ConverterParameter="17"
Path="ActualWidth"
RelativeSource="{RelativeSource TemplatedParent}">
<Binding.Converter>
<xctk:HalfConverter />
</Binding.Converter>
</Binding>
</Grid.MaxWidth>
<xctk:TrimmedTextBlock
FontWeight="Bold"
Text="{TemplateBinding SelectedObjectTypeName}"
TextTrimming="CharacterEllipsis" />
</Grid>
<Grid Margin="5,0,0,0">
<Grid.MaxWidth>
<Binding
ConverterParameter="17"
Path="ActualWidth"
RelativeSource="{RelativeSource TemplatedParent}">
<Binding.Converter>
<xctk:HalfConverter />
</Binding.Converter>
</Binding>
</Grid.MaxWidth>
<xctk:TrimmedTextBlock Text="{TemplateBinding SelectedObjectName}" TextTrimming="CharacterEllipsis" />
</Grid>
</StackPanel>
</StackPanel>
<ListView
x:Name="multiSelectObjectsNamePanel"
Background="Transparent"
Foreground="{TemplateBinding Foreground}"
BorderThickness="0"
Visibility="Collapsed">
<ListView.ItemTemplate>
..
.
``