ng ОШИБКА в Невозможно прочитать свойство 'карта' из неопределенного

Question

> ng.cmd run app:ionic-cordova-serve --host=localhost --port=8100 --

platform=browser
[ng] Compiling @angular/core : es2015 as esm2015
[ng] i ｢wds｣: Project is running at http://localhost:8100/webpack-dev-server/
[ng] i ｢wds｣: webpack output is served from /
[ng] i ｢wds｣: 404s will fallback to //index.html
[ng] chunk {cordova} cordova.js, cordova.js.map (cordova) 50.6 kB [entry] [rendered]
[ng] chunk {main} main.js, main.js.map (main) 1.97 kB [initial] [rendered]
[ng] chunk {polyfills} polyfills.js, polyfills.js.map (polyfills) 154 kB [initial] [rendered]
[ng] chunk {runtime} runtime.js, runtime.js.map (runtime) 6.15 kB [entry] [rendered]
[ng] chunk {styles} styles.js, styles.js.map (styles) 114 kB [initial] [rendered]
[ng] chunk {vendor} vendor.js, vendor.js.map (vendor) 340 kB [initial] [rendered]
[ng]
[ng] ERROR in Cannot read property 'map' of undefined
[ng] Date: 2020-04-12T08:00:55.810Z - Hash: 089fd22601a9cc0c5b24 - Time: 27699ms

Я не использовал переменную карты нигде в проекте. Я не могу понять эту ошибку.

Вот мой код:

    import { Injectable } from "@angular/core";
    import {  AngularFireAuth } from 'angularfire2/auth';
    import {  AngularFireDatabase } from 'angularfire2/database';
    import { first, map, switchMap, tap } from 'rxjs/operators';
    import * as firebase from 'firebase/app';
    import { of } from 'rxjs';
    import { NativeStorage } from '@ionic-native/native-storage/ngx';



    @Injectable({

        providedIn:'root'

    })
    export class Presence{

        id = '';

    constructor(private fbAuth:AngularFireAuth,
        private db:AngularFireDatabase,
        private nSotrage: NativeStorage){
            this.wholeMethods();

        }
        wholeMethods(){
            this.updateOnUser().subscribe();
            this.updateOnDisconnect().subscribe();
            this.updateOnAway();
            this.nSotrage.getItem('id').then(res=>{
                this.id = res;
            });
        }

        //get user pressence

        getPresence(uid: string){
           return this.db.object('Users/'+this.id).valueChanges();
            // return console.log('present: ', this.db.object('status/'+this.id).valueChanges());
        }

        //to get userinfo

        getUser(){

            return this.fbAuth.authState.pipe(first()).toPromise();
        }

        //to set userPresence status

        async setPresence(status: string){

            const user = await this.getUser();
            if(user){
                return this.db.object('Users/'+user.uid).update({status, timestamp:this.timestamp});

            }
        }

        get timestamp(){
            return firebase.database.ServerValue.TIMESTAMP;
        }

        updateOnUser(){
            const connection = this.db.object('.info/connected').valueChanges().pipe(
                map( connected => connected ? 'online' : 'offline')
            );
            return this.fbAuth.authState.pipe(
                switchMap(user => user ? 
                    connection : of('offline')),
                    tap(status => this.setPresence(status))

            );
        }

        updateOnAway(){
            document.onvisibilitychange = (e) =>{
                if(document.visibilityState == 'hidden'){
                    this.setPresence('away');
                }else{
                    this.setPresence('online');
                }
            };
        }



        updateOnDisconnect(){

            return this.fbAuth.authState.pipe(
                tap(user =>{
                    if (user) {
                        this.db.object('Users/'+user.uid).query.ref.update({status:'offline', 
                        timestamp:this.timestamp});
                    }
                })
            );

        }


    }