The UI freezes if the DropDownContent of RadDropDownButton has a native Run element and the CloseOnPopupMouseLeftButtonUp property is set to True.
MouseLeave event is never fired after we change the Them of the controls from a control located in the DropDownContent. Therefor the controls IsMouseOver property is true and looks like it is hovered.
Arg_COMException in some cases when used with RoutedUICommand
Update the Buttons AutomationPeer to use the AutomationProperties attached properties. As a workaround you can create a custom button control deriving from RadButton. That would allow you to create a custom AutomationPeer class that can return the AutmationProperties.Name value to a narrator application
When a RadMenu/RadContextMenu is used as DropDownContent of a SplitButton/DropDownButton, the DropDownContent cannot be closed after sub menu items are displayed
DropDownButton's DropDownContent blinks when its template and its parent's ControlTemplate are changed at runtime