I have the following `Navigation.vue` component:

```
<template>
  <div>
    {{user.first_name}}
  </div>
</template>

<script>
  import { mapActions, mapGetters } from 'vuex'

  export default {
    name: 'hello',
    methods: {
      ...mapActions(['myAccount'])
    },

    mounted: function () {
      if (localStorage.getItem('access_token')) {
        this.myAccount()
      }
    },

    computed: {
      ...mapGetters(['user'])
    }
  }
</script>

```

This code returns:

```
[Vue warn]: Error in render function: "TypeError: Cannot read property 'first_name' of null"

```

but the strange thing is that user first name is showing correctly. What am I doing wrong?