Convert RTF to Text Format through Script Component

I have pre written VB Code in Script Component for converting RTF Data to Plain Text 

    Public Overrides Sub Input0_ProcessInputRow(ByVal Row As Input0Buffer)
        '
        Try

            Dim enc As New System.Text.UTF8Encoding()
            Dim RTFConvert As RichTextBox = New RichTextBox
            RTFConvert.Rtf = enc.GetString(Row.Body.GetBlobData(0, Convert.ToInt32(Row.Body.Length)))
            Row.ConvertedBody.ResetBlobData()
            Row.ConvertedBody.AddBlobData(System.Text.Encoding.UTF8.GetBytes(RTFConvert.Text))
        Catch E As Exception
            E.Message.ToString()
        End Try
    End Sub

End Class

I am getting a Weird Error in which Script Component Converts RTF Data for only 9000 rows and does not convert after that.Can anyone please let me know alternative..Thanks 

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Srikanth