It really looks like it's the same issue as #4584 Everything is fine with your code to this point:

DocView.vue

<template lang="pug">
  div.view
    section
      section-def
        dt(slot="title" v-html="doc.title")
        dd(slot="desc" v-html="doc.desc")
    section
      section-header Examples

but when you add <slot> after that, it breaks with isRootInsert error.

Correct. It also only breaks because the slotted components have default slots of their own. Notice the named slot which contains a component with no slot, it works just fine.

Since the patch was in the codegen, you will need to use updated vue-template-compiler as well. I cloned your repo and tested locally using everything from my local branch and it seems to be working correctly (all the views render properly), so I think it is indeed caused by the same bug.

If you want to test it yourself, you can clone the Vue repo, build everything and link vue and vue-template-compiler and vue-server-renderer into your project.

(great job on vuetify, btw!)

Thanks Evan, didn't think about those packages as well. Appreciate all the help.