This has been one of the main development issues too, along with too few volunteers in all areas. Probably there are also some process issues as well. Regardless, Beta code base is a year old… Numerous fixes to prevent backup breakages (and allow fast Recreate if need be) are not in Beta.
Eventually new Beta should come. 2.0.4.33 canary is probably very good, although also very new.
Major area of worry to me personally is that the Stop button change in 2.0.4.29 adds lots of issues.
For your experimental/testing machine, a more potentially surprising release like a canary might fit, however if you’re using it as a proxy for family backup (including fixes), sharing pain might be best.
Generally my advice on reliability is that Beta code is, pretty much by definition, still not fully stable, meaning it should not be the only backup for anything you’d seriously hate to lose. Restarting fresh sometimes is the best path for future backups, however there are numerous levels of recovery from problems if restores are what you want. Duplicati.CommandLine.RecoveryTool.exe uses a different restore method than the usual GUI or CommandLine restores, and is more tolerant of any problems. Beyond that, there’s a Python script mainly intended to have no dependency at all on Duplicati code:
Independent restore program (yet another thing to test with new Stop code – I tested RecoveryTool).
If you still have files on the destination, you might be able to recover your backup, but whether or not you can continue will depend on test. The recent Canary Recreate is usually vastly faster than before.
It can’t overcome all possible errors though, and only more test will find out how healthy destination is.
You can also get a preview of whether or not it will work by running Canary on some system to try the direct restore. If upgrading a system on Duplicati now, downgrading can be harder, due to DB format changes. This is where the backup files mentioned can come in handy. Upgrade via GUI then a quick downgrade by manual removal of the upgrade (and use of a backup DB if needed) if you like will work.
Downgrading / reverting to a lower version talks about this, but simpler is upgrade-and-stay-upgraded-until-Beta, or finding some other system to play with, where there’s nothing you care about in Duplicati.
I haven’t tested, but for Recreate button (as opposed to a DIY), the plan for allowing rollback may differ: