In your HTML change
<div id="tabstrip" kendo-tab-strip>
with
<div id="tabstrip" kendo-tab-strip="tabstrip">
And change your controller below
$scope.activateSecondTab = function() {
$scope.tabstrip.select(1);
};
I saved a working example in http://embed.plnkr.co/OjKwKRjupDWwNPifqzm2/preview
!