Nextcloud and ownCloud offers a updater app. This is possible to use, but please do not forget to do all "pre work" before a update, like disable 3rd party apps, create backup on your local device, ...
That is not required if you have our Auto update addon!
If your update failes because of an issue caused not by the server nor the updater app, like forgot disable 3rd party apps,.... and you cannot access the cloud anymore, we can only offer to REINSTALL the cloud!
No data or settings will be restored, its a fresh install. If you need the exist cloud up and running, you can order tech tasks, so manually work by a tech to get this fixed. This is required because a failed update can cause FULL data loss, cloud crash,... and takes much time to investigate and fix the issue. This is not included in the OwnCube support as its not a server, nor OwnCube issue, its a user failure.
Thank you for your understanding.
Tech tasks/hours can be ordered: https://billing.owncube.com/cart.php?gid=35