Expander problem

Hello,

I cannot found thread for Expander, so I get it here...

I defined this:

<StackPanel Grid.Column="1" Orientation="Vertical">
<telerikPrimitives:RadExpanderControl>
<telerikPrimitives:RadExpanderControl.ExpandableContent>
<Grid>
<telerikPrimitives:RadBusyIndicator AnimationStyle="AnimationStyle1" ...
<telerikDataControls:RadListView>

</telerikDataControls:RadListView>
</Grid>
</telerikPrimitives:RadExpanderControl.ExpandableContent>
</telerikPrimitives:RadExpanderControl>
<telerikPrimitives:RadExpanderControl x:Name="expanderSelectedAdvertisements"
IsExpanded="True" IsExpandable="False">
<telerikPrimitives:RadExpanderControl.ExpandableContent>
<Grid>
<telerikDataControls:RadListView x:Name="telerikListSelectedAdvertisements">
</telerikDataControls:RadListView>
</Grid>
</telerikPrimitives:RadExpanderControl.ExpandableContent>
</telerikPrimitives:RadExpanderControl>
</StackPanel>

When I start app, I get immediately this error:

System.Runtime.InteropServices.COMException: No installed components were detected.
Multiple animations in the same containing Storyboard cannot target the same property on a single element.
   at Windows.UI.Xaml.VisualStateManager.GoToState(Control control, String stateName, Boolean useTransitions)
   at Telerik.UI.Xaml.Controls.RadContentControl.SetVisualState(String state, Boolean animate)
   at Telerik.UI.Xaml.Controls.RadContentControl.UpdateVisualState(Boolean animate)
   at Telerik.UI.Xaml.Con

Why? When I use Expander in other view and expandable content defined as ExpandableContentTemplate, all working right.