When I use the New Horizontal/Vertical Tab Group context menu options to split my DockableContents, the SaveLayout works fine but the RestoreLayout doesn't restore it properly. The restored layout is as if I never used the New Horizontal/Vertical Tab Group
I initally did not have any resizing panels under docking manager. All I had was a documentpane. With this setup and using New Horizontal/Vertical Tab Group and then trying to restore layout, would throw an Object Reference not set to an instance of
an object error. Using the resizing panels, I was able to restore the layout without any error but it wouldn't restore it properly as described in the above paragraph.