NullReferenceException is thrown if you set the IsChecked property of the RadToggleSwitchButton before the button is added to the visual tree. This happens only when the switch animation is disabled.
To work this around, you can set the AnimationManager.IsAnimationEnabled property of the button to True initially. And then set it back to False on Loaded of the button.
When the SelectionMode of RadAutoCompleteBox is changed, the search text is cleared. However, this clears only the Text property of the underlying TextBox element. The SearchText property of the control is not cleared.
To work this around, you can manually set the SearchText after setting the SelectionMode.this.autoCompleteBox.SelectionMode = AutoCompleteSelectionMode.Multiple;
this.autoCompleteBox.SearchText = null;
This happens because in the current version of Telerik, the IsTopmost of the ToolWindow that host the floating pane is set to True. That was needed for a related new functionality, but it brings a major behavioral change in the RadDocking control.
To work this around, you can subscribe to the ToolWindowCreated event of RadDocking and set the IsTopmost property of the creating ToolWindow to False.
private void RadDocking_ToolWindowCreated(object sender, Telerik.Windows.Controls.Docking.ElementCreatedEventArgs e)
{
var window = (ToolWindow)e.CreatedElement;
window.IsTopmost = false;
}