Wpf Page Navigation Null Reference Exception

Question

I'm trying to implement multi-page navigation in a WPF app, running into some trouble after navigation to a page that has dependency injection.

public partial class DependencyViewer : Page
    {
        private Point dependencyCanvasLast;
        private DependencyViewerViewModel _viewModel;
 public DependencyViewer(DependencyViewerViewModel viewModel)
        {
            Log.Information("Dependency viewer constructor!");
            _viewModel = viewModel;
            InitializeComponent();
            ....
        }
    }

When I attempt to navigate from my MainWindow...

 _mainFrame.Navigate(new Uri(senderData.LinkUrl, UriKind.Relative));

I get this stacktrace

System.NullReferenceException
  HResult=0x80004003
  Message=Object reference not set to an instance of an object.
  Source=System.Private.CoreLib
  StackTrace:
   at System.DefaultBinder.BindToMethod(BindingFlags bindingAttr, MethodBase[] match, Object[]& args, ParameterModifier[] modifiers, CultureInfo cultureInfo, String[] names, Object& state)
   at MS.Internal.Xaml.Runtime.DynamicMethodRuntime.CreateInstanceWithCtor(Type type, Object[] args)
   at MS.Internal.Xaml.Runtime.DynamicMethodRuntime.CreateInstanceWithCtor(XamlType xamlType, Object[] args)
   at MS.Internal.Xaml.Runtime.ClrObjectRuntime.CreateInstance(XamlType xamlType, Object[] args)
   at MS.Internal.Xaml.Runtime.PartialTrustTolerantRuntime.CreateInstance(XamlType xamlType, Object[] args)
   at System.Xaml.XamlObjectWriter.Logic_CreateAndAssignToParentStart(ObjectWriterContext ctx)
   at System.Xaml.XamlObjectWriter.WriteStartMember(XamlMember property)
   at System.Xaml.XamlWriter.WriteNode(XamlReader reader)
   at System.Windows.Markup.WpfXamlLoader.TransformNodes(XamlReader xamlReader, XamlObjectWriter xamlWriter, Boolean onlyLoadOneNode, Boolean skipJournaledProperties, Boolean shouldPassLineNumberInfo, IXamlLineInfo xamlLineInfo, IXamlLineInfoConsumer xamlLineInfoConsumer, XamlContextStack`1 stack, IStyleConnector styleConnector)
   at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
   at System.Windows.Markup.WpfXamlLoader.LoadBaml(XamlReader xamlReader, Boolean skipJournaledProperties, Object rootObject, XamlAccessLevel accessLevel, Uri baseUri)
   at System.Windows.Markup.XamlReader.LoadBaml(Stream stream, ParserContext parserContext, Object parent, Boolean closeStream)
   at System.Windows.Application.LoadBamlStreamWithSyncInfo(Stream stream, ParserContext pc)
   at MS.Internal.AppModel.AppModelKnownContentFactory.BamlConverter(Stream stream, Uri baseUri, Boolean canUseTopLevelBrowser, Boolean sandboxExternalContent, Boolean allowAsync, Boolean isJournalNavigation, XamlReader& asyncObjectConverter)
   at MS.Internal.AppModel.MimeObjectFactory.GetObjectAndCloseStream(Stream s, ContentType contentType, Uri baseUri, Boolean canUseTopLevelBrowser, Boolean sandboxExternalContent, Boolean allowAsync, Boolean isJournalNavigation, XamlReader& asyncObjectConverter)
   at System.Windows.Navigation.NavigationService.GetObjectFromResponse(WebRequest request, WebResponse response, Uri destinationUri, Object navState)
   at System.Windows.Navigation.NavigationService.DoNavigate(Uri source, NavigationMode f, Object navState)
   at System.Windows.Navigation.NavigateQueueItem.Dispatch(Object obj)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   at System.Windows.Threading.DispatcherOperation.InvokeImpl()
   at MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(Object obj)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at MS.Internal.CulturePreservingExecutionContext.Run(CulturePreservingExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Windows.Threading.DispatcherOperation.Invoke()
   at System.Windows.Threading.Dispatcher.ProcessQueue()
   at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
   at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.Run()
   at System.Windows.Application.RunDispatcher(Object ignore)
   at System.Windows.Application.RunInternal(Window window)
   at System.Windows.Application.Run()
   at MyApp.App.Main()

  This exception was originally thrown at this call stack:
    [External Code]

If I simply remove the dependency injected class then it works as expected.

Here is the dependency injection code in App.xaml.cs

public App()
        {
            ServiceCollection services = new ServiceCollection();
            ConfigureServices(services);
            serviceProvider = services.BuildServiceProvider();
        }

        private void ConfigureServices(ServiceCollection services)
        {
            Log.Logger = new LoggerConfiguration()
                .MinimumLevel.Debug()
                .WriteTo.Console()
                .CreateLogger();
            Serilog.Core.Logger seriLog = new LoggerConfiguration()
                .MinimumLevel.Debug()
                .WriteTo.Console()
                .CreateLogger();

            ILoggerFactory logger = LoggerFactory.Create(logging =>
            {
                logging.AddSerilog(seriLog);

            });
            //ILogger myLogger = logger.CreateLogger();
            services.AddSingleton(logger);
            services.AddMemoryCache();

            services.AddDbContext<BPDbContext>(options =>
            {
                options.UseSqlServer(Configuration.GetConnectionString("BpDatabase"));
                options.UseLoggerFactory(logger);
            });
            services.AddTransient<IProcessRepo, ProcessRepo>();
            services.AddTransient<IProcessNameDependencyRepo, ProcessNameDependencyRepo>();


            services.AddTransient<IProcessService, ProcessService>();
            services.AddTransient<IProcessNameDependencyService, ProcessNameDependencyService>();
            services.AddSingleton<DependencyViewerViewModel>();
            services.AddSingleton<MainWindow>();

        }

The dependency injection does work for my MainWindow -

public partial class MainWindow : Window
    {
        private readonly IProcessService _processService;
        private readonly IProcessNameDependencyService _processNameDependencyService; 
        private Point dependencyCanvasLast;
        public MainWindow(IProcessService processService, IProcessNameDependencyService processNameDependencyService)
        {
            MainWindowViewModel vm = new MainWindowViewModel();
            DataContext = vm;
            InitializeComponent();
            ...
        }
    }