title: Items collection must be empty before using ItemsSource with checkbox control in datagrid wpf
body: <p>This error only occurs when I add this following XAML code :
  <img src="https://i.stack.imgur.com/x8rfR.png" alt="enter image description here"></p>
  
  <pre><code> &lt;DataGridTemplateColumn Header="Ist aktiv" IsReadOnly="True"&gt;
       &lt;DataGridTemplateColumn.CellTemplate&gt;
           &lt;DataTemplate&gt;
               &lt;CheckBox IsChecked="{Binding IsActiveBool}"  /&gt;
            &lt;/DataTemplate&gt;
       &lt;/DataGridTemplateColumn.CellTemplate&gt;
   &lt;/DataGridTemplateColumn&gt;
  
  &lt;/DataGrid&gt;
  </code></pre>