message: Vue: undefined click handler error on clicking checkbox items in modern theme
diff: <template>
  - <div :class="getHeaderClass(element)" @click="element.clickTitleFunction">
  + <div :class="getHeaderClass(element)" @click="function() { if (element.hasInput) element.focus(); return true; }">
  <h5
  v-if="element.hasTitle"
  :class="getTitleClass(element)"
  