System.Windows.Data Warning: 40: 'IsChecked' property not found on 'object' ''RibbonQuickAccessToolBar'?....

Hi,

System.Windows.Data Warning: 40 : BindingExpression path error: 'IsChecked' property not found on 'object' ''RibbonQuickAccessToolBar' (Name='')'. BindingExpression:Path=IsChecked; DataItem='RibbonQuickAccessToolBar' (Name=''); target element is 'RibbonToggleButton' (Name='PART_OverflowButton'); target property is 'NoTarget' (type 'Object')

This is an odd warning message because I'm not using nor do I have it defined:

Main window Shell.xaml:

<RibbonWindow 
    x:Class="NatsarTurahStudyMaster.Shell"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:NatarV="clr-namespace:Natsar.TurahStudyUI.Views;assembly=Natsar.TurahStudyUI"
    xmlns:NatarVM="clr-namespace:Natsar.TurahStudyUI.ViewModels;assembly=Natsar.TurahStudyUI"
    Title="Natsar Turah Study Master" Height="768" Width="1024" WindowStartupLocation="CenterScreen" WindowState="Maximized"
    ScrollViewer.HorizontalScrollBarVisibility="Auto" ScrollViewer.VerticalScrollBarVisibility="Auto"><RibbonWindow.Resources><DataTemplate DataType="{x:Type NatarVM:TurahStudyUIViewModel}"><NatarV:TurahStudyUIView x:Name="Natsar"/></DataTemplate></RibbonWindow.Resources></RibbonWindow>

.
...
<Ribbon.QuickAccessToolBar><RibbonQuickAccessToolBar ><RibbonButton 
			x:Name="QATButton1" 
			SmallImageSource="/Natsar.Common;component/Resources/SmallIcon.png" /><RibbonButton 
			x:Name="QATButton2" 
			SmallImageSource="/Natsar.Common;component/Resources/SmallIcon.png" /></RibbonQuickAccessToolBar></Ribbon.QuickAccessToolBar>
..
.

So why am I getting this warning message?  I would like to get rid of it.

Thanks!...

Code is like a box of chocolates!...