Hi Virtue,
When I looked at the knowledge browser article for your error it says that the file extension may not be correct.
http://kb.reckon.com.au//issue_view.asp?ID=402
Can you please confirm whether it is a .qbw, .qbb or .qbm file that you are trying to open?
Feel free to email me directly at sally@samsolutions.com.au if you need any further assistance.
Kind regards, Sally
Are you trying to open the file by double clicking on the file, or are you trying to access it via opening the QuickBooks software and then selecting to open a company file?
Kind regards,
Sally