Error: formControlName must be used with a parent formGroup directive. You'll want to add a formGroup directive - Angular reactive forms

I have the following template. I'm trying to get to grips with reactive forms but am having a problem.

<form [formGroup]="guestForm" novalidate>
    <div class="panel-body">
        <form>
    		<div class="col-md-12 col-sm-12">
    			<div class="form-group col-md-3 col-sm-6">
    				<label>First Name*	</label>
    				<input formControlName="firstname" type="text" class="form-control input-sm">
    			</div>
    		</div>
    	</form>
    </div>
</form>

Then in my component I have:

@Component({
    selector: 'guest-input',
    templateUrl: './guest-input.component.html',
})
export class GuestInputComponent implements OnInit {
    @Input()
    guest: Guest;

    guestForm: FormGroup;
    
    constructor(private _fb: FormBuilder) { }

    ngOnInit() {
        this.guestForm = this._fb.group({
            firstname: ['test', [Validators.required, Validators.minLength(3)]]
        });
    }
}

This all looks fine to me but for some reason I am getting:

> Error: Uncaught (in promise): Error: formControlName must be used with a parent formGroup directive. You'll want to add a formGroup directive and pass it an existing FormGroup instance (you can create one in your class).

I thought I had declared this in my <form>.

You have nested form tag inside form tag with FormGroup directive, remove it:

<form [formGroup]="guestForm" novalidate>
    <div class="panel-body">
        <form> -> Remove this
            <div class="col-md-12 col-sm-12">
                <div class="form-group col-md-3 col-sm-6">
                    <label>First Name*  </label>
                    <input formControlName="firstname" type="text" class="form-control input-sm">
                </div>
            </div>
        </form> -> Remove this
    </div>
</form>

In modelDrivenForms, [formGroup]="guestForm" should be in the parent element

<div class="form-group col-md-3 col-sm-6" [formGroup]="guestForm">
  <label>First Name*  </label>
  <input formControlName="firstname" type="text" class="form-control input-sm">
</div>

When you take form-control without formGroup.

Error code:

<ul class="list-unstyled noti-list m-0">
<li class="d-flex align-items-center">
  
  <div class="custom-switch ml-auto">
    <input
      formControlName="promotionMaterial"
      (change)="onChange($event)"
      class="tgl tgl-light tgl-primary"
      id="promotionMaterial"
      type="checkbox"
    />
    <label class="tgl-btn m-0" for="promotionMaterial"></label>
  </div>
</li>
<li class="d-flex align-items-center">
 
  <div class="custom-switch ml-auto">
    <input formControlName="offer" (change)="onChange($event)" class="tgl tgl-light tgl-primary" id="offer" type="checkbox" />
    <label class="tgl-btn m-0" for="offer"></label>
  </div>
</li>
<li class="d-flex align-items-center">
  <div class="custom-switch ml-auto">
    <input
      formControlName="termsAndConditions"
      (change)="onChange($event)"
      class="tgl tgl-light tgl-primary"
      id="termsAndConditions"
      type="checkbox"
    />
    <label class="tgl-btn m-0" for="termsAndConditions"></label>
  </div>
</li>

In [Error code] I take "formControlName" so it does not work for me.

Solution:

<ul class="list-unstyled noti-list m-0">
<li class="d-flex align-items-center">
  
  <div class="custom-switch ml-auto">
    <input
      [formControl]="promotionMaterial"
      class="tgl tgl-light tgl-primary"
      id="promotionMaterial"
      type="checkbox"
    />
    <label class="tgl-btn m-0" for="promotionMaterial"></label>
  </div>
</li>
<li class="d-flex align-items-center">
 
  <div class="custom-switch ml-auto">
    <input [formControl]="offer class="tgl tgl-light tgl-primary" id="offer" type="checkbox" />
    <label class="tgl-btn m-0" for="offer"></label>
  </div>
</li>
<li class="d-flex align-items-center">
  <div class="custom-switch ml-auto">
    <input
      [formControl]="termsAndConditions"
      class="tgl tgl-light tgl-primary"
      id="termsAndConditions"
      type="checkbox"
    />
    <label class="tgl-btn m-0" for="termsAndConditions"></label>
  </div>
</li>

In solution i take [formControl] insted of formControlName its working fine

Those error are so not descriptive... In my case - it turned up that I have doubled formControlName='...' inside my child component.

Parent component:

<div [formGroup]="formGroup">
    <quill-text-editor formControlName="my_control"></quill-text-editor>
</div>

quill-text-editor component template:

<quill-editor
  formControlName="my_control" <--- I've deleted this to fix the error
  (onFocus)="onEditorFocus()"
  (onBlur)="onEditorBlur()"
></quill-editor>
<hr>
<div class="toolbar">
  <div class="tool">
    (...)

<div class="col-md-12" formArrayName="educations">
</div>

ts file code

educations: this.formBuilder.array([]),

Or

<form [formGroup]="manageOrderForm">

</form>

ts file code import { Router } from '@angular/router';

@Component({
  selector: 'app-order',
  templateUrl: './order.component.html',
  styleUrls: ['./order.component.css']
})
export class OrderComponent implements OnInit {

  manageOrderForm: any;
}