This option allows to limit functionality of the spreadsheet if working period is expired on customer's PC, or he does not provide a valid activation data (password/activation code/serial number).
Scenario for using this feature is very simple:
IsWorkbookActivated( <Workbook Object> ) method of the LockXLS Runtime object allows to determine if workbook has been activated properly.
So, you should select Allow to open workbook if activation failed and use IsWorkbookActivated method to limit functionality of the locked workbook.
Example of using IsWorkbookActivated method:
Dim bWorkbookActivated as Boolean ' declare variable for LockXLS Runtime object Dim oLockXLS As Object ' create LockXLS Runtime object Set oLockXLS = CreateObject("LockXLSRuntime.Connect") ' call command bWorkbookActivated = oLockXLS.IsWorkbookActivated( ThisWorkbook ) ' release LockXLS Runtime object Set oLockXLS = Nothing