Vue.js PWA, vuex: 'An unknown error occured when fetching the script'

Question

I have the following setup:

1. Vue PWA starter
2. Vuex store
3. Persist plugin to have data available offline

The sw registers properly and also loads the cached files containing my vue app when offline. The problem: The data that's stored in the localStorage doesn't show up, although it is available in the localStorage.

In Chrome's Application tab I see the error An unknown error occured when fetching the script. There's no assigned line of code from the worker or anything else.

So right now I don't know whether the problem is my worker, the plugin or something else. Are there any good approaches to tackle such 'magic' problems?

BTW: I left the service worker as is from the Vue PWA starter.

Store initialisation if it helps:

const localStorageConfig = new VuexPersistence({
  key: 'someAppCode',
});

export default new Vuex.Store({
  modules: {
    user,
    client,
    tours,
  },
  plugins: [localStorageConfig.plugin],
});