Recovery from Time Machine when no bootable back-ups appear.
So I'm working on a Mac with a Time Machine drive attached to it. The Time Machine drive backs up normally every hour, day, week, etc.
I boot from recovery mode (Command-R on startup) and enter macOS Utilities. I then erase the internal drive and then try to restore from the Time Machine backup. It sees the Time Machine drive but states there are no bootable backups to recover from. Not a single one. So nothing can be restored that way. And yet nothing is being excluded from the backup so why would that be?
The solution seems to be to erase the internal drive, reinstall macOS and then migrate the users' data and applications across.
Still, surely it should be able to recover a bootable system as usual?
Any ideas good people?