2.15.3. Changes and migration from GateIn 3.1.x

2.15.3.1. Migration of navigation node URL
2.15.3.2. Security changes
2.15.3.3. Default handler
2.15.3.4. Legacy handler
2.15.3.5. Static resource handler
2.15.3.6. portal.war's web.xml changes
2.15.3.7. Dashboard changes
2.15.3.8. Removing unused files

The navigation controller implies a migration of the client code that is coupled to several internal APIs of GateIn. The major impact is related to anything dealing with URL:

Creation of an URL representing a resource managed by the portal: navigation node or UI component.
Using HTTP request related information.