I’m completely unable to upgrade now. The web page always shows that creating a backup failed. Is there any way to skip this step during the upgrade process? When I use the upgrade command on the command line, it says that there is no updated version
Sounds like @tflidd addressed your situation, but did want to respond to this part because it comes up a lot: occ upgrade is not the Updater (though it is generally utilized after a new version of Nextcloud gets installed - either by running it manually or letting the Updater run it when it’s done with everything else).
Noting this more for future searchers.
The Updater = updater.phar whereas occ upgrade is only useful after a successful Updater run.
And, yes, I know this is confusing due to the similar naming.