Stuck after an upgrade to Desktop App 7.1? How to go back to 6.x for ownCloud Server (Classic)

[DeepDiver1975]

Who this is for

You were using the ownCloud Desktop App 6.x with an ownCloud Server (ownCloud Classic / oc10) account. The client then got upgraded to 7.1 — and now your account no longer connects. Reinstalling 6.x didn't help — the client just shows a warning and closes.

This can happen in several ways: a Linux distribution upgrading the package automatically, or a manual update on Windows or macOS where the jump to 7.x wasn't expected. Whichever way you got here, this post explains why it happens and how to get back to a working 6.x setup without losing your account configuration or re-syncing everything.

💡 Before upgrading at any time in the future, please read the release notes at https://github.com/owncloud/client/releases. They exist precisely to flag breaking changes like this one, and a quick read would have warned that 7.x drops ownCloud Server support.

Background: 7.0 removed ownCloud Server support

Starting with Desktop App version 7.0, the client no longer supports ownCloud Server — it only connects to ownCloud Infinite Scale. If you need to keep using ownCloud Server, you must stay on a 6.x client.

So when a 7.x client is pointed at an ownCloud Classic server, the connection can no longer work as before. That is expected behaviour, not a bug in your setup.

Why you can't just reinstall 6.x

The Desktop App records which version last wrote its configuration. When you start a client whose major version is lower than the one stored in the configuration (i.e. starting 6.x after 7.1 has already run), the client deliberately refuses to start: it shows a warning that the settings were created by a newer version, and then quits. This guard exists because a newer configuration may use features an older client doesn't understand.

Because the 7.1 client already rewrote your configuration and stamped it as "7.1", a fresh 6.x install hits this guard immediately.

The good news: your old 6.x configuration was backed up automatically

Every time the Desktop App starts after a version change, it makes a backup copy of your configuration before updating it. The backup sits right next to the live configuration and is named like:

owncloud.cfg.backup_20260115_103000_6.0.0.12345

(the pattern is owncloud.cfg.backup_<date>_<time>_<old version>)

Because you were upgraded from 6.x, there is a backup file that still records your original 6.x configuration. Restoring it makes a reinstalled 6.x client see a 6.x configuration again — so it starts normally and reconnects to your existing ownCloud Classic account.

Where the configuration lives

OS	Configuration folder
Linux	~/.config/ownCloud/
Windows	%APPDATA%\ownCloud\ (e.g. C:\Users\<you>\AppData\Roaming\ownCloud)
macOS	~/Library/Preferences/ownCloud/

The live configuration file is owncloud.cfg; the backups are the owncloud.cfg.backup_* files in the same folder.

Step-by-step downgrade

1. Quit the Desktop App completely — close it from the system tray / menu bar, don't just close the window.

2. Open the configuration folder for your operating system (see the table above). Make sure hidden files and folders are visible.

3. Find your 6.x backup. Look for a file named owncloud.cfg.backup_…_6.x.x…. If there are several, pick the newest one that ends in a 6.x version. Note its full name.

4. Replace the 7.1 client with 6.x.

   • Uninstall the 7.1 client.
   • Install the latest 6.x Desktop App.

5. Restore the backup configuration. In the configuration folder:

   • Rename the current owncloud.cfg to something else (e.g. owncloud.cfg.7.1) so you keep it as a safety copy.
   • Make a copy of your chosen 6.x backup and name the copy owncloud.cfg.

   Tip: copy, don't move — keep the original .backup_… file untouched in case you need it again.

6. Start the 6.x Desktop App. It reads the restored 6.x configuration, recognises your ownCloud Classic account, and resumes syncing your existing local folder. Because the sync state is preserved, it won't re-download everything.

If there is no 6.x backup file

If you can't find an owncloud.cfg.backup_…_6.x… file (for example, it was cleaned up), you can set the account up again on 6.x:

1. Quit the client and (optionally) move the 7.1 owncloud.cfg aside.
2. Install and start 6.x, then add your ownCloud Classic account again.
3. When choosing the local folder, point it at your existing sync folder. The client detects the previous sync state and avoids a full re-download — only changes are reconciled.

While reusing an existing folder, don't change files locally or on the server at the same time, to avoid sync conflicts.

Prevent this in the future

Before applying any client update — automatic or manual, on any platform — read the release notes first: https://github.com/owncloud/client/releases. They call out breaking changes such as the removal of ownCloud Server support, so you can decide before upgrading whether a new version still fits your setup. Be especially careful with any "automatic update" mechanism that could jump you to 7.x while you still rely on ownCloud Server.

Notes & caveats

• Restoring an older configuration is not an officially supported downgrade path, but it works because it relies on the client's own automatic configuration backup.
• Keep the set-aside 7.1 owncloud.cfg and the original .backup_… files until you have confirmed 6.x is working.
• This applies to connecting the desktop client to ownCloud Server (Classic / oc10) only. If you are moving to ownCloud Infinite Scale, stay on 7.x instead.