Error with ion-label - TypeError: Cannot read property 'children' of null

Hi everyone!

I am getting an error in my app. When I use an ion-item with ion-label + ion-input / ion-chkbox i get this error:

TypeError: Cannot read property ‘children’ of null

When I remove the ion-label works fine!

Error Example:

<ion-item no-lines>
    <ion-label floating>TEXT HERE</ion-label>
    <ion-checkbox [(ngModel)]="pageDocument.accept"></ion-checkbox>
</ion-item>

Working Example:

<ion-item no-lines>
     <ion-checkbox [(ngModel)]="pageDocument.accept"></ion-checkbox>
 </ion-item>

Whats is the problem with the code? Thanks in advance!