Since Desktop App 7.0, the client only connects to ownCloud Infinite Scale — support for ownCloud Server (ownCloud Classic / oc10) was removed. If your client was upgraded to 7.1 (by a Linux distro update, or a manual update on Windows/macOS), your ownCloud Server account will no longer connect, and simply reinstalling 6.x won’t work: the client refuses to start on a configuration written by a newer major version.
The good news: the client automatically backs up your configuration before each upgrade, so your original 6.x setup can be restored without re-adding the account or re-syncing.
I’ve written up the full background and step-by-step recovery (for Linux, Windows and macOS) here:
Stuck after an upgrade to Desktop App 7.1? How to go back to 6.x for ownCloud Server (Classic) · owncloud · Discussion #3 · GitHub
And a reminder for everyone: read the release notes before upgrading — Releases · owncloud/client · GitHub — they flag breaking changes like this one.
3 Likes
Thanks, unfortunately too late for me. My installation on Kubuntu 25.10 got clobbered by the update. ChatGPT figured it out for me in the end.
Seriously, pushing a breaking change over a regular update channel is bad style. Nobody expects a functional or security update to break the installation without warning, or reads (and understands) the release notes for dozens of packages in advance. I’ve got no idea and no control over which server software my provider runs.
3 Likes
As per semantic versioning which we are following: breaking changes are done on major upgrades.
6.0.3 to 7.1.0 is a major version upgrade - breaking changes are to be expected.
Package maintainers not reading release notes and pulling in major version bumps without a single review is the real problem here.
1 Like
Thanks for the heads-up.
As a nixpkgs maintainer for owncloud, I will have to rename it to owncloud6 and stop maintaining owncloud 7 onwards. Time to switch to something else, during winter slow days 
2 Likes