Hi support, I've mixed RibbonWindow Sample and Prism with ReagionManager and RadDocking in this sample. When I try to dock a derived RadPane (e.g. OutputView or others) in center of the compass menu the derived RadPane Header is not shown as a tab in the split container. Only pure RadPane instances (c.f. "_regionManager.RegisterViewWithRegion("DockingRegion", typeof(RadPane)); " in FileServicesModule class will dock in correct manner.