On respecte le contrat Serializable.

@@ -13,9 +13,9 @@ import java.util.List;
 @RequestScoped
 public class ListCountriesView implements Serializable {
 
-    private SharedService sharedService;
+    private transient SharedService sharedService;
 
-    private List<Country> countries;
+    private transient List<Country> countries;
 
     public ListCountriesView() {
     }