Форма не может одновременно являться дочерней и родительской формой MDI. ссылается на "Me"

Public Class ParentForm
    Private Sub ExitMenuItem_Click(sender As Object, e As EventArgs) Handles ExitMenuItem.Click
        Close()
    End Sub
 
    Private Sub WindowCascadeMenuItem_Click(sender As Object, e As EventArgs) Handles WindowCascadeMenuItem.Click
        Me.LayoutMdi(System.Windows.Forms.MdiLayout.Cascade)
    End Sub
 
    Private Sub WindowTileMenuItem_Click(sender As Object, e As EventArgs) Handles WindowTileMenuItem.Click
        Me.LayoutMdi(System.Windows.Forms.MdiLayout.TileHorizontal)
    End Sub
 
    Private Sub NewMenuItem_Click(sender As Object, e As EventArgs) Handles NewMenuItem.Click
        Dim newChild As New ChildForm()
        newChild.MdiParent = Me
        newChild.Show()
    End Sub
End Class

Imports System.Windows.Forms
 
Public Class MDIParent1
 
    Private Sub ShowNewForm(ByVal sender As Object, ByVal e As EventArgs) Handles NewToolStripMenuItem.Click, NewToolStripButton.Click, NewWindowToolStripMenuItem.Click
        ' Создать новый экземпляр дочерней формы.
        Dim ChildForm As New System.Windows.Forms.Form
        ' Сделать ее дочерней для данной формы MDI перед отображением.
        ChildForm.MdiParent = Me
 
        m_ChildFormNumber += 1
        ChildForm.Text = "Окно " & m_ChildFormNumber
 
        ChildForm.Show()
    End Sub
 
    Private Sub OpenFile(ByVal sender As Object, ByVal e As EventArgs) Handles OpenToolStripMenuItem.Click, OpenToolStripButton.Click
        Dim OpenFileDialog As New OpenFileDialog
        OpenFileDialog.InitialDirectory = My.Computer.FileSystem.SpecialDirectories.MyDocuments
        OpenFileDialog.Filter = "Текстовые файлы (*.txt)|*.txt|Все файлы (*.*)|*.*"
        If (OpenFileDialog.ShowDialog(Me) = System.Windows.Forms.DialogResult.OK) Then
            Dim FileName As String = OpenFileDialog.FileName
            ' TODO: добавьте здесь код открытия файла.
        End If
    End Sub
 
    Private Sub SaveAsToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles SaveAsToolStripMenuItem.Click
        Dim SaveFileDialog As New SaveFileDialog
        SaveFileDialog.InitialDirectory = My.Computer.FileSystem.SpecialDirectories.MyDocuments
        SaveFileDialog.Filter = "Текстовые файлы (*.txt)|*.txt|Все файлы (*.*)|*.*"
 
        If (SaveFileDialog.ShowDialog(Me) = System.Windows.Forms.DialogResult.OK) Then
            Dim FileName As String = SaveFileDialog.FileName
            ' TODO: добавить код для сохранения содержимого формы в файл.
        End If
    End Sub
 
 
    Private Sub ExitToolsStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles ExitToolStripMenuItem.Click
        Me.Close()
    End Sub
 
    Private Sub CutToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles CutToolStripMenuItem.Click
        ' Использовать My.Computer.Clipboard для помещения выбранного текста или изображений в буфер обмена
    End Sub
 
    Private Sub CopyToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles CopyToolStripMenuItem.Click
        ' Использовать My.Computer.Clipboard для помещения выбранного текста или изображений в буфер обмена
    End Sub
 
    Private Sub PasteToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles PasteToolStripMenuItem.Click
        'Использовать My.Computer.Clipboard.GetText() или My.Computer.Clipboard.GetData для получения информации из буфера обмена.
    End Sub
 
    Private Sub ToolBarToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles ToolBarToolStripMenuItem.Click
        Me.ToolStrip.Visible = Me.ToolBarToolStripMenuItem.Checked
    End Sub
 
    Private Sub StatusBarToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles StatusBarToolStripMenuItem.Click
        Me.StatusStrip.Visible = Me.StatusBarToolStripMenuItem.Checked
    End Sub
 
    Private Sub CascadeToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles CascadeToolStripMenuItem.Click
        Me.LayoutMdi(MdiLayout.Cascade)
    End Sub
 
    Private Sub TileVerticalToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles TileVerticalToolStripMenuItem.Click
        Me.LayoutMdi(MdiLayout.TileVertical)
    End Sub
 
    Private Sub TileHorizontalToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles TileHorizontalToolStripMenuItem.Click
        Me.LayoutMdi(MdiLayout.TileHorizontal)
    End Sub
 
    Private Sub ArrangeIconsToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles ArrangeIconsToolStripMenuItem.Click
        Me.LayoutMdi(MdiLayout.ArrangeIcons)
    End Sub
 
    Private Sub CloseAllToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles CloseAllToolStripMenuItem.Click
        ' Закрыть все дочерние формы указанного родителя.
        For Each ChildForm As Form In Me.MdiChildren
            ChildForm.Close()
        Next
    End Sub
 
    Private m_ChildFormNumber As Integer
 
End Class