VueJS not rendering in IE11

The issue here was ES6 style JavaScript within the markup. Example:

<div class="tabs tab_select" data-group="tabs" data-ref="room" v-on:click="(event) => { toggleTab(event, property) }">

Needed to be:

<div class="tabs tab_select" data-group="tabs" data-ref="room" v-on:click="toggleTab(event, property)">