Problem: I've used the File Menu > Restore from Backup option, but when I relaunch Studiometry there is still no data in the program.
You need to make sure when you select Restore From Backup that you're restoring from a backup that actually contains data.
In a situation where Studiometry does not load the data correctly, it will notify you and continue to function as usual. This means it will create backups based on the currently loaded data, which would be basically empty. What you should do is check your backup folder for a backup that has a larger file size, such as a couple hundred KB. If you sort the folder by date, you can most likely see when the data loss occurred and simply restore from the back right before the data loss to get all of your data back.