TiledMapTileLayer cannot be cast to NavigationTiledMapLayer

[DarthYuber]

I did exactly what the guide said:

map = new NavTmxMapLoader().load("res/battlefield001.tmx",params);
navLayer = (NavigationTiledMapLayer) map.getLayers().get("navigation");

But then I get Exception in thread "LWJGL Application" java.lang.ClassCastException: com.badlogic.gdx.maps.tiled.TiledMapTileLayer cannot be cast to org.xguzm.pathfinding.gdxbridge.NavigationTiledMapLayer

I have used a navigation layer in Tiled etc.
What can I do?
Newest libgdx and tiled version.