NullPointerException: the native object does not exist

that’s the error name and it comes on this code:

   ballphy = new RigidBodyControl(5f); //(ballphy is created)
   ballphy.setCcdSweptSphereRadius(1f);  //(here cones the error)
   state.getPhysicsSpace().add(allphy);  //(state is of BulletAppState)

You haven’t set a collisionshape.

The method setCcdSweptSphereRadius bubbles up to a RigidBody object called rBody which is only created when you set a collision shape.

Take a look at the static method CollisionShapeFactory.createDynamicMeshShape(Spatial spatial).

Thanks i will try it

Is the trouble solved?