java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'usager' available as request attribute

I want to save the database in a new user, but I have this bean problem. I do not know what to do, here is the error

thank's for your help.

java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'usager' available as request attribute

Controller

@Controller
public class UsagerController {

    @Autowired
    private IUsagerMetier metierUsager;

    @RequestMapping(value="/usagers")
    public String usagers(Model model){
        return "usagers";
    }

    @RequestMapping(value="/nouvelUsager")
    public String nouvelUsager(Model model){
        return "nouvelUsager";
    }

    @RequestMapping(value="/addUsager")
    public String add(Usager U, Model model){

        model.addAttribute("usager" , new Usager());
        metierUsager.addUsager(U);
        return "nouvelUsager"; 
    }

}