This possibly happens because the FTM updater mechanism doesn't show the status of the upgrade, nor a message when it is done. So sometimes people think the upgrade is not working, get frustrated and try to close the program or do something else with it before it has finished upgrading.
1) I get that message maybe once a month or so. When I close the program and reboot Windows, it goes away.
2) I'ts always a good idea to make a backup before upgrading. FTM's method of alerting folks kind of frustrates that idea because unless you happen to see on this board that a new update is available, you don't know about it until you've tried to bring up a file and find that FTM is going to upgrade without giving you a chance to make a backup.
3) What about status of your daily, weekly, monthly, or archival backups?
4) Can you create a New File from scratch with one person in it in .723.? In the Plan Workspace, click on "New Tree". With this one person tree open, can you File > Import as New Tree your old file into this one person file?
4) Can you copy the file and the related Media Folder with Windows Explorer to another spot on your hard disk and bring it up?