fix

com.unity.uiwidgets/Runtime/widgets/navigator.cs

 using Unity.UIWidgets.gestures;
 using Unity.UIWidgets.rendering;
 using Unity.UIWidgets.scheduler2;
+using Unity.UIWidgets.services;
 using SchedulerBinding = Unity.UIWidgets.scheduler2.SchedulerBinding;
 using SchedulerPhase = Unity.UIWidgets.scheduler2.SchedulerPhase;
 
 
                     string description;
                     if (route is TransitionRoute ){
-                        //TransitionRoute transitionRoute = route;
                         description = ((TransitionRoute)route).debugLabel;
                     }
                     else {
                     Dictionary<string, object> settingsJsonable = new Dictionary<string, object> {
                         {"name", settings.name}
                     };
-                    /*if (settings.arguments != null) {
-                        settingsJsonable["arguments"] = jsonEncode(
-                            settings.arguments,
-                            toEncodable: (object _object) => $"{_object}"
-                        );
-                    }*/
+                    if (settings.arguments != null) {
+                        settingsJsonable["arguments"] = JSONMessageCodec.instance.toJson(
+                            settings.arguments);
+                    }
 
                     routeJsonable["settings"] = settingsJsonable;
                 }