Редактор не воспринимает текст - Visual Basic .NET

Public Class Form1
    Private Sub СохранитьToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles СохранитьToolStripMenuItem.Click
        Dim Save As New SaveFileDialog
        Save.Filter = "HTML|*.html|Текстовые файлы|*.txt|RTF-файлы|*.RTF"
        If Save.ShowDialog() = DialogResult.Cancel Then Exit Sub
        Dim File As String = Save.FileName
        If File.EndsWith(".RTF") Or File.EndsWith(".rtf") Then
            RichTextBox1.SaveFile(File, RichTextBoxStreamType.RichText)
        ElseIf File.EndsWith(".TXT") Or File.EndsWith(".txt") Then
            RichTextBox1.SaveFile(File, RichTextBoxStreamType.PlainText)
        ElseIf File.EndsWith(".HTML") Or File.EndsWith(".html") Then
            RichTextBox1.SaveFile(File, RichTextBoxStreamType.PlainText)
        End If
    End Sub
 
    Private Sub ОткрытьToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ОткрытьToolStripMenuItem.Click
        Dim Open As New OpenFileDialog
        Open.Filter = "HTML|*.html|Текстовые файлы|*.txt|RTF-файлы|*.RTF"
        Open.Title = "Сохранить файл "
        Open.CheckPathExists = True
        If Open.ShowDialog = Windows.Forms.DialogResult.OK Then
            Dim File As String = Open.FileName
            If File.EndsWith(".RTF") Or File.EndsWith(".rtf") Then
                RichTextBox1.LoadFile(File, RichTextBoxStreamType.RichText)
            ElseIf File.EndsWith(".TXT") Or File.EndsWith(".txt") Then
                RichTextBox1.LoadFile(File, RichTextBoxStreamType.PlainText)
            ElseIf File.EndsWith(".HTML") Or File.EndsWith(".html") Then
                RichTextBox1.LoadFile(File, RichTextBoxStreamType.PlainText)
            Else
                MsgBox("Не могу открыть файл такого формата")
            End If
        End If
 
    End Sub
 
    Private Sub ОчиститьToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ОчиститьToolStripMenuItem.Click
        RichTextBox1.Text = Nothing
    End Sub
 
    Private Sub ОтменитьToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ОтменитьToolStripMenuItem.Click
        RichTextBox1.Undo()
    End Sub
 
    Private Sub ПовторитьToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ПовторитьToolStripMenuItem.Click
        RichTextBox1.Redo()
    End Sub
 
    Private Sub ШрифтToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ШрифтToolStripMenuItem.Click
        FontDialog1.ShowDialog()
        RichTextBox1.SelectionFont = FontDialog1.Font
    End Sub
 
    Private Sub ЦветToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ЦветToolStripMenuItem.Click
        ColorDialog1.ShowDialog()
        RichTextBox1.SelectionColor = ColorDialog1.Color
    End Sub
 
    Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
        If ListBox1.SelectedItem = "<a></a>" Then
            RichTextBox1.Text = RichTextBox1.Text + "<a href=""""></a>"
        End If
        If ListBox1.SelectedItem = "<div></div>" Then
            RichTextBox1.Text = RichTextBox1.Text + "<div></div>"
        End If
        If ListBox1.SelectedItem = "<img>" Then
            RichTextBox1.Text = RichTextBox1.Text + "<img src="""">"
        End If
    End Sub
 
    Private Sub ТегиToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ТегиToolStripMenuItem.Click
        If ListBox1.Visible = False Then
            ListBox1.Visible = True
        Else
            ListBox1.Visible = False
        End If
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
 
    End Sub
End Class