Site wont load, wants upgrade.

Hi

I have a very small site for my business and wanted to edit it today. The site was generated on this pc using the version of NetObjects currently installed.

When I try and open the .nod file I get a message "This file was created by a later version of NetObjects Fusion 12.0 and can't be opened. Please upgrade to the latest version of NetObjects Fusion 12.0".

If I check for updates there are no updates available. The version I am running is 12.00.0000.5222.

Any help will be much appreciated.

thanks

Andy