Thanks again.
As long as your are backing up correctly, this should work for you if you have corrupted database, or a new computer, or anything else.
I was very worried after reading all these comments, but then I found this very small comment by Vlad, IT SOLVES EVERYTHING, just is sparse in detail. I added detail above.
"Also worth note that there is really easy way to backup and transfer your data:
Just expand all nodes, save the view through Ctrl-S and you will be able to drag hierarchies from this file to some other Tabs Outliner instance, or just use this file on its own. "
Many would like to see the "Backup" feature be a "Sync" feature, to eliminate all this hassle (yes, it's "easy", but when it's something that takes several minutes to do, and you have to do it multiple times every day of your life, it's worth automating).
I see little value to maintaining so many Backups, since Google Chrome has all this history saved for us already. What we really need IMO is to automate the restoring from a single Google Drive backup, to eliminate the need for a human to ever spend time restoring. This: https://tabsoutliner.userecho.com/communities/1/topics/134-sync-tabs-tree