This is most likely because your Family Reunion Organizer data file has gotten corrupted somehow. You need to tell FRO to not open that corrupt file when it starts so that you can restore your latest backup. You do this by deleting the settings file for Family Reunion Organizer.
- Click the Start button in Windows, and in the little search box type FAMREUN.INI and press Enter
- When Windows finds and displays the file, delete that file