"File menu > Restore backup file" is not displayed

celoney

Quicken cannot open the data file because it is damaged. Choose File Backup restore is not showing as an option

Greg_the_Geek

Just change the extension of the backup file from .QDF-backup to .QDF and Open the file.

Sherlock

I suggest you open the backup file.  For example, you may press Ctrl + O or select File > Open Quicken File....  If you don't know the location of the backup files, you may use File > Find Quicken Files....

If you do choose to change the suffix of a backup file as @Greg_the_Geek suggested, I suggest you save a copy of the backup file first.