Ionic2 forms showing error

Ionic Framework ionic-v3
4

Yep, I’ve upgraded my dependencies on my package.json to:

"dependencies": {
    "@angular/common": "2.0.0-rc.4",
    "@angular/compiler": "2.0.0-rc.4",
    "@angular/core": "2.0.0-rc.4",
    "@angular/http": "2.0.0-rc.4",
    "@angular/platform-browser": "2.0.0-rc.4",
    "@angular/platform-browser-dynamic": "2.0.0-rc.4",
    "@angular/router": "2.0.0-rc.2",
    "@angular/forms": "^0.2.0",
    "es6-shim": "^0.35.0",
    "ionic-angular": "^2.0.0-beta.11",
    "ionic-native": "1.3.10",
    "ionicons": "3.0.0",
    "reflect-metadata": "^0.1.3",
    "rxjs": "5.0.0-beta.6",
    "socket.io-client": "^1.4.8",
    "zone.js": "^0.6.12"
  },

and executed npm install,
then updated the code of Angular 2 forms to the latest API:

import { Component } from '@angular/core';
import { Validators } from '@angular/common';
import { REACTIVE_FORM_DIRECTIVES, FormBuilder, FormControl, FormGroup } from '@angular/forms';
import { NavController } from 'ionic-angular';

@Component({
  templateUrl: 'build/pages/account/login/login.html',
  directives: [ REACTIVE_FORM_DIRECTIVES ]
})
export class LoginPage {
  loginForm: FormGroup;

  constructor(
    private nav: NavController,
    builder: FormBuilder
  ) {
    this.loginForm = builder.group({
      'username': [
        '', // default value
        [Validators.required, Validators.minLength(5)]
      ],
      'password': [
        '',
        [Validators.required, Validators.minLength(5)]
      ]
    });
  }

  submit() {
    // submit this.loginForm.value
  ...

and the template:

<form class="list" [formGroup]="loginForm" (ngSubmit)="submit()" novalidate>
  <ion-item>
    <ion-label stacked>Username</ion-label>
    <ion-input type="text" formControlName="username"></ion-input>
  </ion-item>
  <ion-item>
    <ion-label stacked>Password</ion-label>
    <ion-input type="password" formControlName="password"></ion-input>
  </ion-item>
  <ion-buttons>
    <button type="submit" block round>Sign In</button>
  </ion-buttons>
</form>

Note that I prefer the model-driven forms for my apps instead the template driven.
Happy coding!