Property accessor EncodedName on object SPHierarchyNode exception...
You get this exception on your first attempt to open successfully deployed application:
Property accessor 'EncodedName' on object 'Microsoft.SharePoint.Navigation.SPHierarchyNode' threw the following exception:'Microsoft.SharePoint.Navigation.SPHierarchyNode.get_EncodedName()
Sometimes this error appears as an “Unknown Error”.
Most likely that means that there is a conflict between SharePoint tree controls and ASP.NET navigation controls.
Solution
Use SharePointDefault.master or SharePointBasic.Master master page.
See SharePoint master page options for details.