TypeError: this.form._updateTreeValidity is not a function

Question

I am currently using Angular Forms version 2.0.0 and trying to make contact with us modal using the contact form inside.

Immediately after loading ContactComponent I get:

EXCEPTION: this.form._updateTreeValidity is not a function

1. I have already seen some other stack messages suggesting that using FormGroup instead of FormBuilder to initiate a form object in the component constructor is now standard with the new API, so I updated this.

2. I import ReactiveFormsModule and FormsModule along with all the components associated with the form, and the error is not related to the module.

3. My TypeScript does not throw errors at compile time, and Visual Studio Intellisense seems to be able to find all the functions of FormGroup very well, so why does this happen at runtime? ...

My code is:

contact.component.ts:

import { Component, Input, ViewChild } from '@angular/core';
import { ApiService } from '../../../services/api.service';
import { ModalComponent } from 'ng2-bs3-modal/ng2-bs3-modal';
import { Router, ActivatedRoute, Params } from '@angular/router';
import { FormsModule, ReactiveFormsModule, FormGroup, FormControl, Validators } from '@angular/forms';
import 'rxjs/Rx';

declare var jQuery: any;

@Component({
    selector: 'my-contact',
    templateUrl: 'app/modules/footer/contact/contact.html'
})
export class ContactComponent {

    private contactForm: FormGroup;
    private invalidEmail: boolean;
    private invalidSubject: boolean;
    private invalidMessage: boolean;

    constructor(private apiService: ApiService, private router: Router, private route: ActivatedRoute) {
        this.contactForm = new FormGroup({
            emailControl: new FormControl('', <any>Validators.required),
            subjectControl: new FormControl('', <any>Validators.required),
            messageControl: new FormControl('', <any>Validators.required)
        });
    }

    submit() {

        if (this.contactForm.valid) {
            this.apiService.sendMessage(this.contactForm.controls['emailControl'].value, this.contactForm.controls['subjectControl'].value, this.contactForm.controls['messageControl'].value);
        }

        if (!this.contactForm.controls['emailControl'].valid) {
            this.invalidEmail = true;
        }
        if (!this.contactForm.controls['subjectControl'].valid) {
            this.invalidSubject = true;
        }
        if (!this.contactForm.controls['messageControl'].valid) {
            this.invalidMessage = true;
        }

    }

    ngOnInit() {
        this.invalidEmail = false;
        this.invalidSubject = false;
        this.invalidMessage = false;
    }

}

contact.html:

<modal-header class="c-no-border" [show-close]="true">
  <h4 class="modal-title text-uppercase">Send us a message</h4>
</modal-header>

<form novalidate #contactForm [formGroup]="contactForm" (ngSubmit)="submit()">
  <div class="modal-body">
    <div class="form-group">
      <label for="email" class="control-label">Email</label>
      <input name="email" formControlName="emailControl" placeholder="" type="text" class="c-square form-control c-margin-b-20" id="email">
      <div class="c-font-red-1" *ngIf="invalidEmail" style="position: absolute;">*Required</div>
      <label for="subject" class="control-label">Subject</label>
      <input name="subject" formControlName="subjectControl" placeholder="" type="text" class="c-square form-control c-margin-b-20" id="subject">
      <div class="c-font-red-1" *ngIf="invalidSubject" style="position: absolute;">*Required</div>
      <textarea formControlName="messageControl" style="resize: vertical;" class="c-square form-control c-margin-b-20" id="content" (keyup.enter)="submit()"></textarea>
      <div class="c-font-red-1" *ngIf="invalidMessage" style="position: absolute;">*Required</div>
    </div>
  </div>
  <modal-footer class="c-no-padding">
    <button type="button" class="btn c-btn-square c-btn-bold c-btn-uppercase pull-right">Cancel</button>
    <button type="submit" class="btn c-theme-btn c-btn-square c-btn-bold c-btn-uppercase pull-right" style="margin-right: 10px;">Send</button>
  </modal-footer>
</form>

app.module.ts:

import { NgModule, enableProdMode }      from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { Ng2Bs3ModalModule } from 'ng2-bs3-modal/ng2-bs3-modal';
import { QueuesModule }     from './modules/queues/queues.module';
import { OrderModule }     from './modules/order/order.module';
import { AccountModule } from './modules/account/account.module';
import { AdminModule } from './modules/admin/admin.module';
import { routing } from './app.routing';
import { GridModule } from '@progress/kendo-angular-grid';
import { SplashComponent } from './modules/splash/splash.component';
import { ContactComponent } from './modules/footer/contact/contact.component';

import { SharedModule } from './shared/shared.module';
import { EmailValidator } from './shared/utilities/custom-validators'

import { CookieService } from 'angular2-cookie/services/cookies.service';
import { HttpModule, Response } from '@angular/http';
import { StringService } from './services/string.service';
import { ApiService } from './services/api.service';
import { UserService } from './services/user.service';
import { OrderService } from './services/order.service';
import { OrderGuard } from './services/order-guard.service';
import { FooterComponent } from './modules/footer/footer.component';
import { ErrorComponent } from './modules/error/error.component';
import { CustomFormsModule } from "ng2-validation";

@NgModule({
    imports: [
        BrowserModule,
        FormsModule,
        ReactiveFormsModule,
        HttpModule,
        QueuesModule,
        OrderModule,
        AccountModule,
        AdminModule,
        routing,
        GridModule,
        SharedModule,
        Ng2Bs3ModalModule,
        CustomFormsModule
    ],
    declarations: [
        AppComponent,
        SplashComponent,
        FooterComponent,
        ErrorComponent,
        ContactComponent
    ],
    providers: [
        StringService,
        ApiService,
        UserService,
        CookieService,
        OrderService,
        OrderGuard
    ],
    bootstrap: [AppComponent],
    exports: [
    ]
})

export class AppModule {
}

Answer 1

#contactForm, , , NgForm . , , , #tv="ngForm" , . , , .

.

Answer 2

. , constructor()

:

checkInForm: FormGroup;

constructor(){
    this.checkInForm = this.formBuilder.group({});
}