Broken installation - howto backup reinstall - restore

I have got a broken installation of nextcloud in opensuse 15.1. It was working great but I show, as admin a message “click here to upgrade version” and I did it and it fails, after that I realized that I have installed nextcloud through the Opensuse packet manager and upgrades should go this way.
Te point is that I think it may be easier to backup user data, delete nexcloud install it from scratch and recover the backed up data. I have seen some documents explaining the backup process but if i only want to backup alll user data (files, calendar, etc.) but no the system files what should I back up?

best regards

The files are all stored in the data folder. You can find the location in your config.php file. Sharing information is only stored in the database along with many of the app data such as calendar, contacts, etc.

In case the update fails, it depends how far it went. If it failed in an early step, the database was perhaps not changed and it is enough to put the code of the previous version again.

For version managed by packet managers, it would be good to disable the update via webinterface. First contact here would be the packet manager (who perhaps needs to get in touch with the developers if not possible right now).

As it was an instalation on Opensuse made with a rpm package, I reinstalled the previous version. Almost all seems to work fine except some menu items in admin account: +apps, users, which lead to a page with no content. I have created another administrator user and is the same for the new one, so it is not a user related issue.
It woulb be possible to know what files or what is bad to be able to fix it instead of reinstalling?

best regards