Hello!
The right behavior for using panes in Docking is like that: we set/modify PanesSource property, Panes property is initialized by using PanesSource and DockingPanesFactory, panes are created or removed. But when set PanesSource, try to load invalid layout and get an exception, Docking.Panes property is set to null and actual panes is not removed, because we don`t have them in Panes property. This behavior cause problems with resolving panes (because there are old panes in memory, that should have been removed). Can you suggest some sort of validation for layout or ways to clean old panes from memory?