Xzing.Net.mobile Barcode Reader Library causes Exception when using Scan() Method (UWP C# Project)

Question

I want to include and Barcode Reader to my UWP (C#) application. I found XZing.Net.Mobile, which build up on the XZing.Net port.

I followed the given example from the github page and modified it so that it now looks the following way:

public sealed partial class ShoppedPage : Page
{
    MobileBarcodeScanner scanner;
    public ShoppedPage()
    {
        this.InitializeComponent();
        scanner = new MobileBarcodeScanner(Dispatcher);
    }

    private void Scan_Click(object sender, RoutedEventArgs e)
    {

        //-- Config Scanner --//
        scanner.UseCustomOverlay = false;
        scanner.TopText = "Die Kamera auf den Barcode halten";
        scanner.BottomText = "Die Kamera sucht dan automatisch nach Barcodes \r\n\r\n 'Zurück' Tasten benutzen um Scannen abzubrechen";

        scanner.Scan().ContinueWith(t => HandleResult(t.Result));
    }

    private void HandleResult(ZXing.Result result)
    {
        Debug.WriteLine(result?.Text);
    }

}

Now I keep running into the following Exception:

Message : {"Object reference not set to an instance of an object."}

Source : "ZXingNetMobile"

StackTrace : at ZXing.Mobile.ZXingScannerControl.d__13.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at ZXing.Mobile.ScanPage.d__73.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<>c.b__6_0(Object state)\r\n at System.Threading.WinRTSynchronizationContext.Invoker.InvokeCore()

Now my question is did I set up the Libary wrong or used in a wrong way? Maybe is there something I oversee ? Or is there a better C# Uwp friendly Barcode Reader Library which is free to use out there?