c# wpf programm not running

Question

Hallo, ich habe ein kleines programm geschrieben und es stürzt teilweise einfach ab wegen einem Fehler in einer Zeile, den ich eigentlich schon ausgebessert habe

XML Reader (XML Dateien in bin->Debug)

public Form1()
        {
            InitializeComponent();
            dataSet1.ReadXml("notes.xml");
            bindingSource1.DataSource = dataSet1.Tables["Note"];
            dataGridView1.AutoGenerateColumns = true;
        }

        private void readxml_Click(object sender, EventArgs e)
        {
            dataSet1.Clear();
            dataSet1.ReadXml("notes.xml");
        }

        private void delete_Click(object sender, EventArgs e)
        {
           foreach (DataGridViewRow row in dataGridView1.SelectedRows){
                dataGridView1.Rows.Remove(row);
            }
            dataSet1.WriteXml("notes.xml");
        }

        private void dataGridView1_CellEndEdit(object sender, DataGridViewCellEventArgs e)
        {
            bindingSource1.EndEdit();
            dataSet1.WriteXml("notes.xml");
        }

XML Reader + Datenbank

public CDCatalog()
        {
            InitializeComponent();
            sqlDataAdapter1.Fill(dataSet11);
        }

        private void delete_Click(object sender, EventArgs e)
        {
            foreach (DataGridViewRow row in dataGridView1.SelectedRows)
            {
                dataGridView1.Rows.Remove(row);
            }

            endEditUpdate();
        }

        private void update_Click(object sender, EventArgs e)
        {
            sqlDataAdapter1.Fill(dataSet11);
        }

        private void recreate_Click(object sender, EventArgs e)
        {
            OpenFileDialog openFileDialog = new OpenFileDialog();
            openFileDialog.Filter = "xml files |*.xml";
            openFileDialog.ShowDialog();

            foreach (DataRow dataRow in dataSet11.CD.Rows)
            {
                dataRow.Delete();
            }
            dataSet11.CD.ReadXml(openFileDialog.FileName);

            endEditUpdate();
        }

        private void endEditUpdate()
        {
            bindingSource1.EndEdit();
            sqlDataAdapter1.Update(dataSet11);
        }

        private void dataGridView1_CellEndEdit(object sender, DataGridViewCellEventArgs e)
        {
            endEditUpdate();
        }

WPF
MainWindow
Zu NavigationWindow ändern

Page 1

 <Grid Margin="10,0,10,10">
        <Grid.ColumnDefinitions>
            <ColumnDefinition />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="300"></RowDefinition>
            <RowDefinition Height="Auto"></RowDefinition>
        </Grid.RowDefinitions>

        <Grid.Background>
            <ImageBrush ImageSource="northern-lights-gedd43aef9_1280.jpg"/>
        </Grid.Background>
        <Label Grid.Row="0" VerticalAlignment="Center" HorizontalAlignment="Center" FontFamily="Calibri light" 
        FontWeight="Bold" FontSize="38" Foreground="DeepPink">
            Welcome
        </Label>

        <Button Grid.Column="0" Grid.Row="1" Margin="0,10,20,0" Width="125" Height="25" HorizontalAlignment="Right" Click="Button_Click">XML Reader</Button>
    </Grid>
private void Button_Click(object sender, RoutedEventArgs e)
        {
            XMLReader reader = new XMLReader();
            this.NavigationService.Navigate(reader);
        }

Page 2

<Grid Margin="10,0,10,10">
        <Grid.ColumnDefinitions>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="200"></RowDefinition>
            <RowDefinition Height="Auto"></RowDefinition>
        </Grid.RowDefinitions>

        <Grid.DataContext>
            <XmlDataProvider x:Name ="dataProvider" Source="C:\Users\Lisa\Desktop\HTL\4BHIF\C#\WpfBsp\bin\Debug\notes.xml" XPath="Notes"/>
        </Grid.DataContext>

        <DataGrid Name="gridview" ItemsSource="{Binding XPath=Note}" AutoGenerateColumns="False" CellEditEnding="gridview_CellEditEnding">
            <DataGrid.Columns>
                <DataGridTextColumn Header="Author" Binding="{Binding XPath=Author,Mode=TwoWay}"/>
                <DataGridTextColumn Header="Text" Binding="{Binding XPath=Text,Mode=TwoWay}"/>
            </DataGrid.Columns>
        </DataGrid>
    </Grid>
</Page>

DLL Reflection

private void open_Click(object sender, EventArgs e)
        {
            OpenFileDialog dlg = new OpenFileDialog();
            dlg.Filter = "dll files (*.dll) |*.dll;";
            dlg.ShowDialog();
            if (dlg.FileName != null)
            { 
                Assembly dllAssembly = Assembly.LoadFile(dlg.FileName);
                TreeNode treeNode = new TreeNode();

                treeNode.Text = dllAssembly.GetName().Name;
                foreach(Type t in dllAssembly.GetTypes())
                {
                    TreeNode typeNode = new TreeNode();
                    typeNode.Text = t.Name;

                    foreach(MemberInfo m in t.GetMembers())
                    {
                        typeNode.Nodes.Add(m.Name);
                    }
                    treeNode.Nodes.Add(typeNode);
                }
                dllTreeView.Nodes.Add(treeNode);
            }
        }