Firebase When uploading file Error: AppCheck: AppCheck is being used before activate()

I am currently constructing a file upload to my firebase account. But when I do this, I get this error:

Uncaught (in promise) FirebaseError: AppCheck: AppCheck is being used before activate() is called for FirebaseApp [DEFAULT]. Please make sure you call activate() before instantiating other Firebase services. (appCheck/use-before-activation).

What I've done so far:

1. I disabled authentication rules for development purposes. I set rules into this

    rules_version = '2';
    service firebase.storage {
      match /b/{bucket}/o {
        match /{allPaths=**} {
          allow read, write: if request.auth != true;
        }
      }
    }
   

2. I installed firebase into my Vue Cli App using the command:

   npm install --save firebase
   

3. Initialized firebase in my App using the following:

    import firebase from 'firebase/app';
    import "firebase/analytics";
    import "firebase/storage";
    import 'animate.css';
   
    var firebaseConfig = {
      apiKey: "*API KEY*",
      authDomain: "lgu-cantilan-hrms.firebaseapp.com",
      projectId: "lgu-cantilan-hrms",
      storageBucket: "lgu-cantilan-hrms.appspot.com",
      messagingSenderId: "*SENDER ID*",
      appId: "*APP ID*",
      measurementId: "*G-8ZQZT5BCZQ*"
    };
    // Initialize Firebase
    firebase.initializeApp(firebaseConfig);
    firebase.analytics();
   

4. Had this setup in my upload component:

    <template>
      <v-dialog v-model="dialog" max-width="800">
        <template v-slot:activator="{ on, attrs }">
          <v-btn
            elevation=""
            color="blue white--text"
            class="ml-10"
            v-bind="attrs"
            v-on="on"
            @click="dialog = true"
            ><v-icon class="mr-2">mdi-file-outline</v-icon>View Files</v-btn
          >
        </template>
        <v-card>
          <v-toolbar color="red" dark>
            <span class="headline mr-2">Files</span>
            <span class="ml-10">
              {{ employee.last_name }}, {{ employee.first_name }}'s Files</span
            >
          </v-toolbar>
          <v-card-text>
            <div class="pa-5">
              <span class="primary--text overline">Add A File</span>
              <div class="mb-5 mt-2">
                <input type="file" class="ml-2" @change="upload_file" />
                <v-btn small color="" @click="upload"> Submit</v-btn>
              </div>
              <v-divider> </v-divider>
              <Files />
            </div>
          </v-card-text>
        </v-card>
      </v-dialog>
    </template>
   
    <script>
    import Files from "@/components/Files/Files.vue";
    import firebase from "firebase";
    export default {
      components: { Files },
      data() {
        return {
          dialog: false,
          employee: {},
          file_upload: null,
          uploadValue: 0,
        };
      },
      created() {
        this.employee = this.$store.state.user.user_view;
      },
      methods: {
        upload_file(e) {
          this.file_upload = e.target.files[0];
          console.log(this.file_upload);
          // this.picture_url = URL.createObjectURL(this.picture);
        },
        upload() {
          var storageRef = firebase
            .storage()
            .ref(this.employee.first_name + "/" + this.file_upload.name);
          var task = storageRef.put(this.file_upload);
          // monitor progress
          task.on(
            "state_change",
            (snapshot) => {
              this.uploadValue =
                (snapshot.bytesTransferred / snapshot.totalBytes) * 100;
            },
            (error) => {
              console.log(error.message);
            }
          );
   
          // task.on("state_change",)
        },
      },
    };
    </script>
   
    <style></style>
   

But when I click the submit button, console gives me an error saying: Uncaught (in promise):

FirebaseError: AppCheck: AppCheck is being used before activate() is called for FirebaseApp [DEFAULT]. Please make sure you call activate() before instantiating other Firebase services. (appCheck/use-before-activation).

I don't have any idea what this error means. I followed the instructions in the documentation. Any help would be appreciated.