Creating new instance, importing from 12 to current

So I have a 2017 Ubuntu instance of Nextcloud 12. I have clients on this old version, that use cal/card dav for contacts and calendars. I want to create a new server with the up to date version of Ubuntu and nextcloud. I’m curious if I create the new and just import the user files is it going to work or what type of issues will I have doing that as I am so far behind in releases. I can use a 3rd party tool to export and re-import the cal/card dav items but more worried about files, permissions, sharing and the actual database not functioning by doing it this way.

So for others out there. I never got a response but I did successfully get my instance 20.0.1 setup. Setup new NC instance on a VM locally networked, I manually exported any customers’ cal and card davs from the UI, imported them into new (some took a while with a ton of contacts.

The only people using the file part of our cloud instance were people in my company and about 4-5 others. We actually just let the desktop clients sync the files on their PC back to the new server instance after logging in each one and re-authenticating their login in their local browser.

Ofc we made backups before starting any of this and in case there were any issues with files syncing. Worked like a charm though. We did have to reshare any file folders/contact lists or calendars from the user that originally owned them for everything to work properly, luckily that was just 5-6 people we had to deal with.

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