One possible solution could look like this:
Sub Loadbtn_Click(sender As System.Object, e As System.EventArgs) Handles Browse.Click
OpenFD.ShowDialog()
' full path to the file + name
Dim filename As String = OpenFD.FileName
Try
' check if file exists to prevent errors
if (File.Exists(filename)) then
' fetch complete text into as lines
Dim Lines = File.ReadAllLines(filename)
' iterate over each line
For Each Line As String In Lines
Dim lv as new ListViewItem
' take it
lv.Text = Line
' and use it
lv.SubItems.Add(Crypto.AES_Decrypt(Line))
' show it
List.Items.Add(lv)
Next
end if
Catch ex As Exception
' inform the user resp. developer
Console.WriteLine(String.Format("An error occurred: {0}", ex.Message))
End Try
End Sub
As already mentioned use File.ReadAllLines if you want to read the file line by line and don't suppress errors - inform the user or at least the developer (yourself, using a log file or something appropriate).