Cant Bind to '' since it isnt a known property

I have used value=“code” for an ion-checkbox which was working fine in beta 11. Upgraded to RC0 and the the error shows up : Cant bind to value since it isnt a know property of ion-checkbox.

The same thing happened in the signature pad component’s options …

In the angular2 doc you should: put value between bracket: [value]=“whatyouneed” or you should use NgModel

<input [value]=“currentHero.firstName”
(input)=“currentHero.firstName=$event.target.value” >

or

< input
[ngModel]=“currentHero.firstName”
(ngModelChange)=“currentHero.firstName=$event”>

Okay. so I cant use [value] and [(ngModel)] together ?

Why would you need that ?