runtime-core.esm-bundler.js?d2dd:40 [Vue warn]: Property "$store" was accessed during render but is not defined on instance. at <App>

This warning message is related to the use of Vuex store in a Vue component. It indicates that the component is trying to access the `$store` property, but the store is not defined on the component instance.

To resolve this warning, make sure that you have properly installed Vuex and created a store instance, and then inject the store into your Vue app using the `store` option. For example, in your main.js file, you can create a store instance and inject it into the app:

import Vue from 'vue'
import Vuex from 'vuex'
import App from './App.vue'

Vue.use(Vuex)

const store = new Vuex.Store({
  // ...
})

new Vue({
  store, // inject the store into the app
  render: h => h(App)
}).$mount('#app')

Then, in your component, you can access the store using the `$store` property:

<template>
  <div>
    {{ $store.state.someState }}
  </div>
</template>

<script>
export default {
  // ...
}
</script>