Target Unreachable, identifier [userMBean] resolved to null

I have a problem when trying to login service in my java web application. As you can see below, there is the HTTP Status 500 error stacktrace - Internal Server Error. I've tried a few things, such as clearing tomcat and rebooting the server. But nothing happens. I put some sysout to debug and none of them appeared on the console.

    javax.el.PropertyNotFoundException: /index.xhtml @22,99 value="#{usuarioMBean.user.login}": Target Unreachable, identifier [usuarioMBean] resolved to null
com.sun.faces.facelets.el.TagValueExpression.getType(TagValueExpression.java:100)
com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getConvertedValue(HtmlBasicInputRenderer.java:95)
javax.faces.component.UIInput.getConvertedValue(UIInput.java:1046)
javax.faces.component.UIInput.validate(UIInput.java:976)
javax.faces.component.UIInput.executeValidate(UIInput.java:1249)
javax.faces.component.UIInput.processValidators(UIInput.java:712)
javax.faces.component.UIForm.processValidators(UIForm.java:253)
javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1261)
javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1261)
javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1195)
com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:76)
com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:646)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

Follow my MBean

package controle;

import java.util.ArrayList;
import java.util.List;

import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;
import javax.inject.Inject;

import dominio.Pessoa;
import dominio.Sindico;
import dominio.TipoPessoa;
import dominio.Usuario;
import servico.PessoaService;
import servico.SindicoService;
import servico.UsuarioService;

@ManagedBean(name="usuarioMBean")
@SessionScoped
public class UsuarioMBean {

private Usuario user;
private List<Usuario> listaUser;
private UsuarioService UserService;
private Usuario usuarioLogado;
private Pessoa morador;
private Sindico administrador;

@Inject
private PessoaService pessoaService;

@Inject 
private SindicoService administradorService;

public UsuarioMBean(){
    user = new Usuario();
    listaUser = new ArrayList<Usuario>();
    UserService = new UsuarioService(); 
}

public Usuario getUser() {
    System.out.println("return user");
    return user;
}

public void setUser(Usuario user) {
    System.out.println("Set user");
    this.user = user;
}

public List<Usuario> getListaUser() {
    System.out.println("get list user");
    return listaUser;
}

public void setListaUser(List<Usuario> listaUser) {
    System.out.println("setlistauser");
    this.listaUser = listaUser;
}

public Usuario getUsuarioLogado() {
    System.out.println("get user logado");
    return usuarioLogado;
}

public void setUsuarioLogado(Usuario usuarioLogado) {
    System.out.println("set user logado");
    this.usuarioLogado = usuarioLogado;
}

public Pessoa getMorador() {
    System.out.println("get morador");
    return morador;
}

public void setMorador(Pessoa morador) {
    System.out.println("set  morador");
    this.morador = morador;
}

public Sindico getAdministrador() {
    System.out.println("get admin");
    return administrador;
}

public void setAdministrador(Sindico administrador) {
    System.out.println("set admin");
    this.administrador = administrador;
}

public String login(){
    System.out.println("entrou no STRING LOGIN");
    Usuario usuarioBd = new Usuario();

    for (Usuario usuarioTemp : UserService.buscarTodos()){
        if (usuarioTemp.getLogin() == user.getLogin()){
            usuarioBd = usuarioTemp;
        }
    }

    if (usuarioBd.getLogin() != ""){
        if (usuarioBd.getSenha().equals(user.getSenha())){
            usuarioLogado = usuarioBd;

            if (usuarioLogado.getTipoID() == TipoPessoa.morador){

                pessoaService = new PessoaService();
                morador = pessoaService.buscar(usuarioLogado.getLogin());

                return "/index.jsf";
            }else{

                administradorService = new SindicoService();
                //administrador = administradorService.buscar(usuarioLogado.getLogin());

                return "/index.jsf";
            }
        }else{
            FacesMessage msg = new FacesMessage("Senha incorreta");
            msg.setSeverity(FacesMessage.SEVERITY_ERROR);
            FacesContext.getCurrentInstance().addMessage("", msg);
            return null;
        }
    }else{
        FacesMessage msg = new FacesMessage("Usuário não existe");
        msg.setSeverity(FacesMessage.SEVERITY_ERROR);
        FacesContext.getCurrentInstance().addMessage("", msg);
        return null;
    }
}

public String logoff(){
    this.usuarioLogado = null;
    return "/login.jsf";
}



}

And jsf

<!DOCTYPE html> 
<html xmlns="http://www.w3.org/1999/xhtml"
  xmlns:f="http://xmlns.jcp.org/jsf/core"
  xmlns:h="http://xmlns.jcp.org/jsf/html"
  xmlns:p="http://xmlns.jcp.org/jsf/passthrough"
  xmlns:jsf="http://xmlns.jcp.org/jsf"
  xmlns:a="http://xmlns.jcp.org/jsf/passthrough"
>
<h:head>
<title> Condominium::Home </title>

<meta charset="utf-8"/>

<link href="static/css/base.css" rel="stylesheet"  />
<link href="static/css/index.css" rel="stylesheet"  />

  </h:head>
  <h:body>
<div class="content">
  <div class="login_form">
    <h:form>
      <h:inputText class="fields" value="#{usuarioMBean.user.login}" a:placeholder="Usuário"/>
      <h:inputSecret class="fields" value="#{usuarioMBean.user.senha}" a:placeholder="Senha"/>
          <h:commandLink action="#{usuarioMBean.login}" class="submit_button">Logar</h:commandLink>
    </h:form>
  </div>
</div>

<footer>
    <p> Condominium </p>
</footer>