Exception when using extracted template

[Louis]

If I extract the style/template for a RadPropertyGrid to a new ResourceDictionary, when I try to assign an object to the RadPropertyGrid Item property, an exception is thrown.

The exception stack is

{System.Windows.Markup.XamlParseException: Set property 'Telerik.Windows.Controls.StyleManager.BasedOn' threw an exception. [Line: 35 Position: 60] ---> System.ArgumentNullException: Value cannot be null.
Parameter name: defaultStyleKey
   at Telerik.Windows.Controls.Theme.GetResourceValue(Type defaultStyleKey, Theme theme, Theme controlTheme)
   at Telerik.Windows.Controls.Theme.GetThemeStyle(Theme oldTheme, Type defaultStyleKey)
   at Telerik.Windows.Controls.StyleManager.OnBasedOnChanged(DependencyObject d, DependencyPropertyChangedEventArgs args)
   at Telerik.Windows.PropertyMetadata.<>c__DisplayClass1.<Create>b__0(DependencyObject d, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.RaisePropertyChangeNotifications(DependencyProperty dp, Object oldValue, Object newValue)
   at System.Windows.DependencyObject.UpdateEffectiveValue(DependencyProperty property, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, ValueOperation operation)
   at System.Windows.DependencyObject.SetValueInternal(DependencyProperty dp, Object value, Boolean allowReadOnlySet)
   at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value)
   at Telerik.Windows.Controls.StyleManager.SetBasedOn(DependencyObject obj, Theme value)
   --- End of inner exception stack trace ---
   at MS.Internal.XcpImports.MethodEx(IntPtr ptr, String name, CValue[] cvData)
   at MS.Internal.XcpImports.MethodEx(DependencyObject obj, String name)
   at MS.Internal.XcpImports.FrameworkElement_ApplyTemplate(FrameworkElement frameworkElement)
   at System.Windows.Controls.ItemContainerGenerator.LayoutStatesManager.GetElementRoot(Boolean templatesAreGenerated)
   at System.Windows.Controls.ItemContainerGenerator.LayoutStatesManager.Load()
   at System.Windows.Controls.ItemContainerGenerator.System.Windows.Controls.Primitives.IItemContainerGenerator.PrepareItemContainer(DependencyObject container)
   at System.Windows.Controls.ItemsControl.AddVisualChild(Int32 containerIndex, DependencyObject container, Boolean needPrepareContainer)
   at System.Windows.Controls.ItemsControl.AddContainerForPosition(GeneratorPosition position)
   at System.Windows.Controls.ItemsControl.OnItemsChangedHandler(Object sender, ItemsChangedEventArgs args)
   at System.Windows.Controls.ItemContainerGenerator.OnItemAdded(Object item, Int32 index, Boolean suppressEvent)
   at System.Windows.Controls.ItemContainerGenerator.System.Windows.Controls.ICollectionChangedListener.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
   at System.Windows.Controls.WeakCollectionChangedListener.SourceCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
   at System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
   at System.Windows.Controls.ItemCollection.NotifyCollectionChanged(NotifyCollectionChangedEventArgs e)
   at System.Windows.Controls.ItemCollection.System.Windows.Controls.ICollectionChangedListener.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
   at System.Windows.Controls.ItemCollection.EnumerableCollectionView.System.Windows.Controls.ICollectionChangedListener.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
   at System.Windows.Controls.WeakCollectionChangedListener.SourceCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
   at Telerik.Windows.Data.QueryableCollectionView.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
   at Telerik.Windows.Data.QueryableCollectionView.ProcessSynchronousCollectionChangedWithAdjustedArgs(NotifyCollectionChangedEventArgs originalArguments, Int32 adjustedOldIndex, Int32 adjustedNewIndex)
   at Telerik.Windows.Data.QueryableCollectionView.ProcessSynchronousCollectionChanged(NotifyCollectionChangedEventArgs args)
   at Telerik.Windows.Data.QueryableCollectionView.ProcessCollectionChanged(NotifyCollectionChangedEventArgs args)
   at Telerik.Windows.Data.QueryableCollectionView.OnSourceCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
   at Telerik.Windows.Data.QueryableCollectionView.Telerik.Windows.Data.IWeakEventListener<System.Collections.Specialized.NotifyCollectionChangedEventArgs>.ReceiveWeakEvent(Object sender, NotifyCollectionChangedEventArgs args)
   at Telerik.Windows.Data.WeakEvent.WeakListener`1.Handler(Object sender, TArgs args)
   at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
   at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item)
   at System.Collections.ObjectModel.Collection`1.Add(T item)
   at Telerik.Windows.Controls.RadPropertyGrid.GeneratePropertyDefinitions()
   at Telerik.Windows.Controls.RadPropertyGrid.OnItemPropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs args)
   at Telerik.Windows.PropertyMetadata.<>c__DisplayClass1.<Create>b__0(DependencyObject d, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.RaisePropertyChangeNotifications(DependencyProperty dp, Object oldValue, Object newValue)
   at System.Windows.DependencyObject.UpdateEffectiveValue(DependencyProperty property, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, ValueOperation operation)
   at System.Windows.DependencyObject.SetValueInternal(DependencyProperty dp, Object value, Boolean allowReadOnlySet)
   at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value)
   at Telerik.Windows.Controls.RadPropertyGrid.set_Item(Object value)
   at testDocking.MainPage.mainPropertyGrid2_Loaded(Object sender, RoutedEventArgs e)}

using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Telerik.Windows.Controls;
using Telerik.Windows.Controls.Data.PropertyGrid;
using System.Windows.Data;

namespace testDocking
{
public partial class MainPage : UserControl
{
public MainPage()
{
InitializeComponent();
this.mainPropertyGrid2.HorizontalAlignment = HorizontalAlignment.Stretch;
this.mainPropertyGrid2.SizeChanged += new SizeChangedEventHandler(mainPropertyGrid2_SizeChanged);
}

void mainPropertyGrid2_SizeChanged(object sender, SizeChangedEventArgs e)
{
var presenter = this.mainPropertyGrid2.ChildrenOfType<PropertyGridPresenter>()[0];
presenter.Width = this.mainPropertyGrid2.ActualWidth - 2;
}

private void mainPropertyGrid2_Loaded(object sender, RoutedEventArgs e)
{
((RadPropertyGrid)sender).Item = new Person();
var presenter = this.mainPropertyGrid2.ChildrenOfType<PropertyGridPresenter>()[0];
presenter.Width = this.mainPropertyGrid2.Width;
}
}

public class Person
{
public string FirstName { get; set; }
public string LastName { get; set; }
}
}

<UserControl x:Class="testDocking.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
    d:DesignHeight="300" d:DesignWidth="400">
    <Grid x:Name="LayoutRoot" Background="White">
        <telerik:RadDocking   BorderThickness="0" Padding="0">
            <telerik:RadSplitContainer Orientation="Vertical" InitialPosition="DockedLeft">
                <telerik:RadPaneGroup x:Name="propertiesPaneGroup" SelectedIndex="-1">
                    <telerik:RadPane x:Name="propertiesPane" Header="Properties" CanFloat="False" CanUserClose="False" CanDockInDocumentHost="False">
                        <telerik:RadPropertyGrid Name="mainPropertyGrid2" Loaded="mainPropertyGrid2_Loaded"  AutoGeneratePropertyDefinitions="True" Style="{StaticResource RadPropertyGridStyle1}" DescriptionPanelVisibility="Collapsed">
                        </telerik:RadPropertyGrid>
                    </telerik:RadPane>
                </telerik:RadPaneGroup>
            </telerik:RadSplitContainer>
        </telerik:RadDocking>
    </Grid>
</UserControl>

App.xaml:

<Application xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             x:Class="testDocking.App"
             >
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="ResourceDictionary1.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>

ResourceDictionary1.xaml:

<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation">
<SolidColorBrush x:Key="ControlOuterBorder" Color="#FF848484"/>
<!-- Resource dictionary entries should be defined here. -->
<SolidColorBrush x:Key="ControlInnerBorder" Color="White"/>
<LinearGradientBrush x:Key="PropertyGrid_HeaderBackground" EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="White" Offset="0"/>
<GradientStop Color="#FFCDCDCD" Offset="1"/>
<GradientStop Color="#FFCECECE" Offset="0.42"/>
<GradientStop Color="#FFAFAFAF" Offset="0.43"/>
</LinearGradientBrush>
<SolidColorBrush x:Key="RadioButton_Indicator" Color="Black"/>
<telerik:Office_BlackTheme x:Key="Theme"/>
<SolidColorBrush x:Key="PropertyGrid_SearchIndicator_Background" Color="#FF919191"/>
<Style x:Key="ItemsControlStyle" TargetType="ItemsControl">
<Setter Property="BorderBrush" Value="#FF848484"/>
<Setter Property="BorderThickness" Value="0,0,0,1"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ItemsControl">
<Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Padding="{TemplateBinding Padding}" VerticalAlignment="Top">
<ItemsPresenter/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<DataTemplate x:Key="flatTemplate">
<ItemsControl ItemsSource="{Binding}" Style="{StaticResource ItemsControlStyle}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<telerik:PropertyGridField Content="{Binding}">
<telerik:PropertyGridField.Resources>
<Style x:Key="TextBox" telerik:StyleManager.BasedOn="{StaticResource Theme}" TargetType="TextBox">
<Setter Property="Padding" Value="3,2,0,2"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="BorderBrush" Value="Transparent"/>
</Style>
<Style x:Key="CheckBox" telerik:StyleManager.BasedOn="{StaticResource Theme}" TargetType="CheckBox">
<Setter Property="Margin" Value="3,2,0,2"/>
</Style>
<Style x:Key="RadComboBox" telerik:StyleManager.BasedOn="{StaticResource Theme}" TargetType="telerik:RadComboBox">
<Setter Property="ItemContainerStyle">
<Setter.Value>
<Style telerik:StyleManager.BasedOn="{StaticResource Theme}" TargetType="telerik:RadComboBoxItem"/>
</Setter.Value>
</Setter>
<Setter Property="IsEditable" Value="True"/>
</Style>
</telerik:PropertyGridField.Resources>
<telerik:StyleManager.Theme>
<StaticResource ResourceKey="Theme"/>
</telerik:StyleManager.Theme>
</telerik:PropertyGridField>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</DataTemplate>
<SolidColorBrush x:Key="PropertyGrid_IndentCellBackground" Color="#FFE4E4E4"/>
<SolidColorBrush x:Key="ToggleButton_Indicator" Color="Black"/>
<Style x:Key="PropertyGridToggleButtonStyle" TargetType="telerik:RadToggleButton">
<Setter Property="VerticalContentAlignment" Value="Stretch"/>
<Setter Property="HorizontalContentAlignment" Value="Left"/>
<Setter Property="Height" Value="25"/>
<Setter Property="FontWeight" Value="Bold"/>
<Setter Property="Foreground" Value="#FF000000"/>
<Setter Property="BorderBrush" Value="{StaticResource ControlOuterBorder}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="telerik:RadToggleButton">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver"/>
<VisualState x:Name="Disabled"/>
</VisualStateGroup>
<VisualStateGroup x:Name="CheckStates">
<VisualState x:Name="Checked">
<Storyboard>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="(UIElement.RenderTransform).(RotateTransform.Angle)" Storyboard.TargetName="ExpanderButton">
<EasingDoubleKeyFrame KeyTime="00:00:00.2" Value="180"/>
</DoubleAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderThickness" Storyboard.TargetName="IconOuterBorder">
<DiscreteObjectKeyFrame KeyTime="0:0:0" Value="0,0,0,0"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderThickness" Storyboard.TargetName="IconInnerBorder">
<DiscreteObjectKeyFrame KeyTime="0:0:0" Value="1,1,0,0"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Unchecked"/>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualState x:Name="Focused"/>
<VisualState x:Name="Unfocused"/>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="IconOuterBorder" BorderBrush="{StaticResource ControlOuterBorder}" BorderThickness="0,0,0,1" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Width="25">
<Border x:Name="IconInnerBorder" BorderBrush="{StaticResource ControlInnerBorder}" BorderThickness="1,1,0,1" Background="{StaticResource PropertyGrid_IndentCellBackground}">
<Path x:Name="ExpanderButton" Data="M0,0L1,0 2,0 2,0.99999991 3,0.99999991 3,2 4,2 4,0.99999991 5,0.99999991 5,0 5.9999999,0 7,0 7,0.99999991 5.9999999,0.99999991 5.9999999,2 5,2 5,3 4,3 4,4 3,4 3,3 2,3 2,2 1,2 1,0.99999991 0,0.99999991z" Fill="{StaticResource ToggleButton_Indicator}" HorizontalAlignment="Center" Height="5" RenderTransformOrigin="0.5,0.5" VerticalAlignment="Center" Width="7">
<Path.RenderTransform>
<RotateTransform/>
</Path.RenderTransform>
</Path>
</Border>
</Border>
<Border BorderBrush="{StaticResource ControlOuterBorder}" BorderThickness="0,0,0,1" Grid.ColumnSpan="2" Grid.Column="1">
<Border BorderBrush="{StaticResource ControlInnerBorder}" BorderThickness="0,1,1,1" Background="{StaticResource PropertyGrid_IndentCellBackground}">
<ContentPresenter x:Name="PART_ContentPresenter" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Border>
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<telerik:BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
<telerik:GroupingItemsSourceConverter x:Key="GroupingItemsSourceConverter"/>
<DataTemplate x:Key="groupTemplate">
<ItemsControl ItemsSource="{Binding ., Converter={StaticResource GroupingItemsSourceConverter}}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Border BorderBrush="{StaticResource ControlOuterBorder}" BorderThickness="0,1,0,0" Margin="0,-1,0,0">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<telerik:RadToggleButton x:Name="expandCollapseButton" BorderBrush="{x:Null}" Content="{Binding Key}" IsChecked="True" Style="{StaticResource PropertyGridToggleButtonStyle}"/>
<ContentPresenter x:Name="PART_ContentPresenter" ContentTemplate="{StaticResource flatTemplate}" Content="{Binding Items}" Grid.Row="1" Visibility="{Binding IsChecked, Converter={StaticResource BooleanToVisibilityConverter}, ElementName=expandCollapseButton}"/>
</Grid>
</Border>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</DataTemplate>
<telerik:ItemTemplateConverter x:Key="ItemTemplateConverter" FlatTemplate="{StaticResource flatTemplate}" GroupTemplate="{StaticResource groupTemplate}"/>
<SolidColorBrush x:Key="PropertyGrid_DescriptionBorderBrush" Color="White"/>
<SolidColorBrush x:Key="PropertyGrid_DescriptionBackground" Color="#FFBFBFBF"/>
<ControlTemplate x:Key="RadPropertyGridTemplate" TargetType="telerik:RadPropertyGrid">
<Border x:Name="PART_RootElement" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}">
<Grid x:Name="PART_PropertyGridContainer" Background="{TemplateBinding Background}">
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
<RowDefinition Height="*"/>
<RowDefinition Height="auto"/>
</Grid.RowDefinitions>
<Border x:Name="Header" BorderBrush="{StaticResource ControlOuterBorder}" BorderThickness="0,0,0,1" Margin="0,0,0,-1">
<Border BorderBrush="{StaticResource ControlInnerBorder}" BorderThickness="1" Background="{StaticResource PropertyGrid_HeaderBackground}">
<Grid Margin="1">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<telerik:RadRadioButton x:Name="groupButton" Margin="0,0,3,0" telerik:StyleManager.Theme="{StaticResource Theme}" Visibility="{TemplateBinding SortAndGroupButtonsVisibility}" Width="28">
<ToolTipService.ToolTip>
<ToolTip telerik:LocalizationManager.ResourceKey="Categorize" telerik:StyleManager.Theme="{StaticResource Theme}"/>
</ToolTipService.ToolTip>
<Path Data="M7.0000019,8.9999981 L16.999998,8.9999981 L16.999998,9.9999981 L7.0000019,9.9999981 z M7.0000019,6.9999995 L16.999998,6.9999995 L16.999998,7.9999995 L7.0000019,7.9999995 z M0,6 L3.9999998,8.5 L0,11 z M6.999999,3.0000055 L16.999996,3.0000055 L16.999996,4.0000052 L6.999999,4.0000052 z M7.0000019,0.99999905 L16.999998,0.99999905 L16.999998,1.9999989 L7.0000019,1.9999989 z M0,0 L4,2.5000002 L0,5.0000005 z" Fill="{StaticResource RadioButton_Indicator}" Height="11" Stretch="Fill" StrokeThickness="0" Width="17"/>
</telerik:RadRadioButton>
<telerik:RadRadioButton x:Name="sortButton" Content="A-Z" Grid.Column="1" IsChecked="True" telerik:StyleManager.Theme="{StaticResource Theme}" Visibility="{TemplateBinding SortAndGroupButtonsVisibility}" Width="28">
<ToolTipService.ToolTip>
<ToolTip telerik:LocalizationManager.ResourceKey="Alphabetical" telerik:StyleManager.Theme="{StaticResource Theme}"/>
</ToolTipService.ToolTip>
</telerik:RadRadioButton>
<TextBox x:Name="searchAsYouTypeTextBox" Grid.Column="2" HorizontalAlignment="Stretch" Margin="2,0,0,0" telerik:TextBoxBehavior.SelectAllOnGotFocus="True" Text="{Binding FilterText, ElementName=PropertyGridPresenter, Mode=TwoWay}" telerik:StyleManager.Theme="{StaticResource Theme}" telerik:TextBoxBehavior.UpdateTextOnEnter="True" telerik:TextBoxBehavior.UpdateTextOnTextChanged="True" Visibility="{TemplateBinding SearchBoxVisibility}"/>
<Path Grid.Column="2" Data="M8.4939966,1.9999999 C6.5610008,1.9999999 4.9939971,3.5670033 4.9939971,5.5 C4.9939971,7.4329967 6.5610008,9 8.4939966,9 C10.426993,9 11.993997,7.4329967 11.993997,5.5 C11.993997,3.5670033 10.426993,1.9999999 8.4939966,1.9999999 z M8.4939976,0 C11.531564,-8.7786177E-08 13.993998,2.4624338 13.993998,5.5 C13.993998,8.5375662 11.531564,11 8.4939976,11 C7.3549109,11 6.2967014,10.65372 5.4188957,10.060686 L5.3678761,10.025319 L1.4142134,13.978982 L0,12.564768 L3.9563832,8.6083851 L3.9333115,8.5751028 C3.3402777,7.6972966 2.9939978,6.6390872 2.9939978,5.5 C2.9939978,2.4624338 5.4564314,-8.7786177E-08 8.4939976,0 z" Fill="{StaticResource PropertyGrid_SearchIndicator_Background}" HorizontalAlignment="Right" Height="14" Margin="4" Stretch="Fill" StrokeThickness="2" Visibility="{TemplateBinding SearchBoxVisibility}" Width="14"/>
</Grid>
</Border>
</Border>
<Border BorderBrush="{StaticResource ControlOuterBorder}" BorderThickness="0,1,0,1" Grid.Row="1">
<ScrollViewer x:Name="PART_ItemsScrollViewer" ScrollViewer.HorizontalScrollBarVisibility="Auto" telerik:StyleManager.Theme="{StaticResource Theme}" ScrollViewer.VerticalScrollBarVisibility="Auto">
<telerik:PropertyGridPresenter x:Name="PropertyGridPresenter" ContentTemplate="{Binding IsChecked, Converter={StaticResource ItemTemplateConverter}, ElementName=groupButton}" LabelColumnWidth="{Binding LabelColumnWidth, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" PropertyDefinitions="{Binding PropertyDefinitions, RelativeSource={RelativeSource TemplatedParent}}" telerik:StyleManager.Theme="{StaticResource Theme}"/>
</ScrollViewer>
</Border>
<Border x:Name="PART_DescriptionPanel" BorderBrush="{StaticResource PropertyGrid_DescriptionBorderBrush}" BorderThickness="0,1,0,0" Background="{StaticResource PropertyGrid_DescriptionBackground}" MinHeight="75" Grid.Row="2" Visibility="{TemplateBinding DescriptionPanelVisibility}">
<StackPanel Orientation="Vertical">
<TextBlock FontWeight="Bold" Margin="5" Text="{Binding SelectedPropertyDefinition.DisplayName, ElementName=PropertyGridPresenter}"/>
<TextBlock Margin="5" TextWrapping="Wrap" Text="{Binding SelectedPropertyDefinition.Description, ElementName=PropertyGridPresenter}"/>
</StackPanel>
</Border>
</Grid>
</Border>
</ControlTemplate>
<SolidColorBrush x:Key="ControlBackground" Color="White"/>
<SolidColorBrush x:Key="ControlForeground" Color="#FF000000"/>
<Style x:Key="RadPropertyGridStyle1" TargetType="telerik:RadPropertyGrid">
<Setter Property="Template" Value="{StaticResource RadPropertyGridTemplate}"/>
<Setter Property="Background" Value="{StaticResource ControlBackground}"/>
<Setter Property="BorderBrush" Value="{StaticResource ControlOuterBorder}"/>
<Setter Property="Foreground" Value="{StaticResource ControlForeground}"/>
<Setter Property="BorderThickness" Value="1"/>
</Style>
</ResourceDictionary>

[Maya]

Hello Louis,

Actually, it is a know issue and we are working on resolving it. You may follow its progress in our Public Issue Tracking System. Please excuse us for the inconvenience.
 

All the best,
Maya
the Telerik team