I having a problem with the radmenuitem popup after adding the dropshadoweffect on the styling of border.
<
Popup x:Name="PART_Popup" VerticalOffset="0" HorizontalOffset="0">
<Border BorderBrush="{StaticResource RadMenu_PopupShadowBorder2}" BorderThickness="0,0,0,0">
<Border BorderBrush="{StaticResource RadMenu_PopupShadowBorder1}" BorderThickness="0,0,0,0">
<Border BorderBrush="{StaticResource BorderOuterBrush}" BorderThickness="0">
<Border.Effect>
<DropShadowEffect BlurRadius="8" Direction="330" ShadowDepth="3" Opacity="0.85"/>
</Border.Effect>
<Border.Background>
<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="#E5040608"/>
<GradientStop Color="#E50F161E" Offset="0.5"/>
<GradientStop Color="#D83C536A" Offset="1"/>
</LinearGradientBrush>
</Border.Background>
<Grid>
<ItemsPresenter />
</Grid>
</Border>
</Border>
</Border>
</Popup>