Ionic Modal iOS Error

<!--
  Generated template for the ModalInformarTelefoneFacebook page.

  See http://ionicframework.com/docs/v2/components/#navigation for more info on
  Ionic pages and navigation.
-->
<ion-header>

    <ion-navbar color="secondary">
        <ion-title>Informe os Dados</ion-title>
        <ion-buttons start>
            <button ion-button (click)="dismiss()">
                    <span ion-text color="primary" showWhen="ios">Cancelar</span>
                <ion-icon name="md-close" showWhen="android,windows"></ion-icon>
            </button>
        </ion-buttons>
    </ion-navbar>

</ion-header>


<ion-content padding>

    <ion-card>
        <ion-card-content text-center>
            Para finalizar, precisamos que nos informe seu telefone para contato
        </ion-card-content>

    </ion-card>

    <form (ngSubmit)="retornarDados()" #registerForm="ngForm">
        <ion-item>
            <ion-label floating>DDD</ion-label>
            <ion-input type="text" [attr.maxLength]="2" name="ddd" [(ngModel)]="form.ddd" required></ion-input>
        </ion-item>
        <ion-item>
            <ion-label floating>Telefone</ion-label>
            <ion-input type="text" [attr.maxLength]="9"  name="telefone" [(ngModel)]="form.telefone" required></ion-input>
        </ion-item>

        <ion-row padding>
            <button  ion-button color="secondary" block type="submit" [disabled]="!registerForm.form.valid">Salvar</button>
        </ion-row>
    </form>

</ion-content>