title: VB.NET ERROR system.invalidoperationexception
body: <p>I have copied(text:- ctrl-c ctrl-v) a class from one of my previous programs that run without a glitch, into project. Very simple extracts data out of a text file. </p>
  
  <p>On my machine it works like a charm, with Visual Studio 2010 installed. On someone elses machine it crash on start up with a directional error.</p>
  
  <pre><code>EventType : clr20r3     P1 : total_extractor.exe     P2 : 1.0.0.1     
  P3 : 51f64e90     P4 : total_extractor     P5 : 1.0.0.1     P6 : 51f64e90     
  P7 : 4a     P8 : 22     P9 : **system.invalidoperationexception**    
  </code></pre>
  
  <p>The only info I have in the load module is the following:</p>
  
  <pre><code>Option Explicit On
  Public Class frm_Main    
      Private Sub btn_Extract_Click(sender As System.Object, e As System.EventArgs) Handles btn_Extract.Click
          RunTE()
      End Sub    
      Private Sub frm_Main_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
          Me.cbx_Defaults.Items.Add("String Loads | *.det")
          Me.cbx_Defaults.Items.Add("RF | *.det")
          Me.cbx_Defaults.Items.Add("OLOADS | *.f06")
          Me.cbx_Defaults.Items.Add("Properties | *.f06")
      End Sub
      Private Sub cbx_Defaults_SelectedIndexChanged(sender As System.Object, e As System.EventArgs) Handles cbx_Defaults.SelectedIndexChanged
          Dim combostr As String
          combostr = cbx_Defaults.Text   
          If combostr = "RF | *.det" Then
              txt_Begin.Text = "TABLE 6.2: ACD table"
              txt_End.Text = "TABLE 6.3:"
              txt_Skip.Text = "2"
              txt_Filter.Text = "*.det"
          ElseIf combostr = "String Loads | *.det" Then
              txt_Begin.Text = "TABLE 2.1.1:"
              txt_End.Text = "TABLE 2.2.1"
              txt_Skip.Text = "2"
              txt_Filter.Text = "*.det"
          ElseIf combostr = "OLOADS | *.f06" Then
              txt_Begin.Text = "OLOAD    RESULTANT"
              txt_End.Text = "TOTALS"
              txt_Skip.Text = "2"
              txt_Filter.Text = "*.f06"
          ElseIf combostr = "Properties | *.f06" Then
              txt_Begin.Text = "LOAD FACTOR   1.0"
              txt_End.Text = "*** USER"
              txt_Skip.Text = "5"
              txt_Filter.Text = "*.f06"
          End If
      End Sub
  End Class
  </code></pre>
  
  <p>The code uses, <code>My.Computer.FileSystem.OpenTextFileReader</code> and that is about it. 
  The information I get from google, usually is about some data-basing options. This just manipulates text documents? </p>
  
  <p>Anyideas, on how to catch the event? or is it a setting I have set?</p>