0👍
Actually, it is ok to publish your component as UMD. I had to register my component in the Vue instance, like so:
<div id="app">
<polar :item="3">hoi</polar>
</div>
<script>
var app = new Vue({
el: '#app',
components: { polar: vuePolar},
})
</script>
Now it works. I got confused by an example that did not require the component to be registered.
Source:stackexchange.com