It works for me when i used the fromTemplate Methode not the fromTemplateUrl.
// .fromTemplate() method
var template = '<ion-popover-view><ion-header-bar> <h1 class="title">My Popover Title</h1> </ion-header-bar> <ion-content> Hello! </ion-content></ion-popover-view>
But know it is really confusing and hard to edit the html.....