Hello Community

I've tried to build the AccountLocator project from Trailhead. The trailhead checks are all passed, but it dose give me an error "Something has gone wrong. Cannot read property 'lat' of null." every time i open the app and no markers are shown.

If i change the line of code from a) to b) the marker gets placed and there are no errors, but i can't find a solution to reach the function of the AccountLocator. On the Leaflet github i've found an simular error but i can't replicate the given solution.

I', quit new to javascript so i really could need some help with this issue.

Best Regards,
Patrick

a)

L.marker(latLng, {account: account}).addTo(map).on('click', function(event) {
                helper.navigateToDetailsView(event.target.options.account.Id);
            });

b)

var test = [37.784173, -122.401557]
L.marker([test[0],test[1]]).addTo(map);

My current AccountMapController.js

({
    jsLoaded: function(component, event, helper) {
        
        setTimeout(function() {
            var map = L.map('map', {zoomControl: false})
            .setView([37.784173, -122.401557], 14);
            L.tileLayer(
                'https://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer/tile/{z}/{y}/{x}',
                {
                    attribution: 'Tiles © Esri'
                }).addTo(map);
            component.set("v.map", map);
        });
    },
    
    accountsLoaded: function(component, event, helper) {
    
        // Add markers
        var map = component.get('v.map');
        var accounts = event.getParam('accounts');
        for (var i=0; i<accounts.length; i++) {
            var account = accounts[i];
            var latLng = [account.Location__Latitude__s, account.Location__Longitude__s];
            
            //var test = [37.784173, -122.401557]
            //L.marker([test[0],test[1]]).addTo(map);
            
            L.marker(latLng, {account: account}).addTo(map).on('click', function(event) {
                helper.navigateToDetailsView(event.target.options.account.Id);
            });

        }
    },
    
    accountSelected: function(component, event, helper) {
        // Center the map on the account selected in the list
        var map = component.get('v.map');
        var account = event.getParam("account");
        map.panTo([account.Location__Latitude__s, account.Location__Longitude__s]);
    }
    
})