Live .log file watcher in rtb

[CodeBeginer]

Hi,
From ling time I'm fighting with program which would watch specific log file and put last line into textbox.
I tried many things but it didn't work.
1. Put .log file patch to navigate webbrowser, put inner text to richtextbox and put last line to textbox. When i started navigated the log file was opening normaly in notepad and webbrowers show error.

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Try
            WebBrowser1.Navigate(TextBox1.Text)
            Timer1.Enabled = True
        Catch ex As Exception

        End Try
    End Sub

    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
        WebBrowser1.Refresh()
        RichTextBox1.Text = WebBrowser1.Document.Body.InnerText
        TextBox2.Text = RichTextBox1.Lines(RichTextBox1.Lines.Length - 1)
    End Sub

2. Stream plain text direcly to richtextbox and then to textbox but app generating log file stopped saving new logs.

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Try
            Timer1.Enabled = True
        Catch ex As Exception

        End Try
    End Sub

    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick

        RichTextBox1.LoadFile(TextBox1.Text, RichTextBoxStreamType.PlainText)
        TextBox2.Text = RichTextBox1.Lines(RichTextBox1.Lines.Length - 1)
    End Sub

Could you help me with that?