[Bug]: macOS Nextcloud-3.17.0-macOS-vfs and later has severe sync problems

[Sergeij2000]

⚠️ Before submitting, please verify the following: ⚠️

• This is a bug, not a question or a configuration issue.
• This issue is not already reported on Github (I've searched it).
• Nextcloud Server and Desktop Client are up to date. See Server Maintenance and Release Schedule and Desktop Releases for supported versions.
• I agree to follow Nextcloud's Code of Conduct

Bug description

After upgrading the macOS VFS client from 3.16.6 to 3.17.0 and 3.17.1, sync problems start to occur which are signaled by a yellow status icon with exclamation mark. The status window shows the message "Einige Dateien konnten nicht synchronisiert werden! Warnungen siehe unten.", but there are no warnings listet in the activity list. After a short time the warning disappears, but may show again after a while.

Some folders, populated with many subfolders and files are shown as fully synchronized and empty; the web interface of the server shows all files and subfolders and they are accessible through the WebDAV-interface.

Deinstalling and purging all configuration files and cleaning up the Library/CloudProvider folder - and then reinstalling the client doesn't fix the problem. It even happened once that after reinstalling the client during the first sync some folders where deleted on the server without being moved to the trash_folder, forcing me to restore the data from a backup.

Reinstalling the old 3.16.6 client fixes the problems.
...

Steps to reproduce

The problem occured after upgrading von 3.16.6 to 3.17.0.

Expected behavior

The folder sync should work like advertised and expected.

Which files are affected by this bug

Any files and folders can be affected (i.e. shown with size 0 bytes or completely disappear).

Operating system

macOS

Which version of the operating system you are running.

macOS Sequoia Version 15.6.1

Package

Official macOS 12+ universal pkg

Nextcloud Server version

31.0.8

Nextcloud Desktop Client version

3.17.0 and higher

Is this bug present after an update or on a fresh install?

Updated to a major version (ex. 3.3.6 to 3.4.0)

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

Are you using an external user-backend?

• Default internal user-backend
• LDAP/ Active Directory
• SSO - SAML
• Other

Nextcloud Server logs

No log entries regarding the bug.

Additional info

I initiated a scan of the user data on the server using 'nextcloud.occ files:scan USER' after restoring the backup.
Question: As the unsynchronized folders stayed the same through several reinstallations: Is there any client related table in the nextcloud db which stores the actual sync status? Would it help to drop that data to "repair" the client sync? I've attached the debug archives captured during the several reinstallations. For the timeline of the screenshots: The first screenshot is the newest, the last one the oldest. All screenshots are taken over a time of appr. 10s.

[GlacierColt]

Same issue here. Exactly as described. Certain folders do not show any sub-folders and have the Nextcloud icon as a little exclamation mark.

Only thing to add: Disabling and re-enabling virtual files completely bricks virtual files, in finder when viewing the Nextcloud folder (where all the virtual files should be) says "loading..." continuously along with "Nextcloud is signed out" (in finder) even though I am signed in.

Tried reinstalling latest version of Nextclud with no luck, even reset MacOS. Only solution is to use an older version of Nextcloud client with vfs (3.16.6).

[Rello]

Hello,

we are looking into this already. We got the "is signed out" recently reported but not reproduced in a reliable way.
Work in progress

[Sergeij2000]

@GlacierColt
I didn't see the "signed out" message and the yellow exclamation mark disappeared after a couple of seconds when i launched nc client after reinstallation...

[Rello]

Hello,
to post an update: it seem we found the issue for the file provider loosing connection to the server (e.g. shown by the sign-out button). We are testing the fix already...