Kan ikke loade txt filer i richtextbox

Kode 

Imports System.IO
Public Class Form1
    Private Sub Button1_Click(ByVal sender As_ System.Object, ByVal e As System.EventArgs) Handles_ Button1.Click
        ' Create an OpenFileDialog to request a file to open.
        Dim openFile1 As New OpenFileDialog()

        ' Initialize the OpenFileDialog to look for RTF files.
        openFile1.DefaultExt = "*.txt"
        openFile1.Filter = "TXT Files|*.txt"

        ' Determine whether the user selected a file from the OpenFileDialog.
        If (openFile1.ShowDialog() = System.Windows.Forms.DialogResult.OK) And(openFile1.FileName.Length > 0) Then

        ' Load the contents of the file into the RichTextBox.
        RichTextBox1.LoadFile(openFile1.FileName, RichTextBoxStreamType.PlainText)
        End If
    End Sub
End Class