After installing the Scroll Versions plugin, I tried to add a navigation bar following the instructions outlined on this page: http://www.k15t.com/display/VSN/Adding+a+Search+Box+to+the+Navigation+Sidebar
However, once having completed the instructions, I encountered an error messsage saying: "The selected root page could not be found." Refer to the following screenshot:

I've tried different locations for the _SvNavigation page using the Hierarchy; for example, putting the page as a child page of the home page, but with no luck. I'm not sure what's causing the problem, so any help on this would be greatly appreciated.
I am currently using Confluence 4.3.3, with Scroll Versions plugin version 2.0 (evaluation license).