[Bug]: macOS Virtual files VFS not working on Nextcloud 3.15.3

[sjg2203]

⚠️ 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

I am trying to use Virtual files with Nextcloud desktop on macOS, but this functionality does not seem to work.
I installed Nextcloud desktop Virtual files 3.15.3 and skipped the setup part.

I then enabled Virtual files as well as fast sync.

I saw that it scanned over the files currently on the server, though after it seemed it had finished, there was nothing in Users/macos/Library/CloudStorage/Nextcloud-admin@IP (Locations → Nextcloud), it is empty.
The loading wheel keeps turning indefinitely.

I tried to click on the sign-in button on the top right but welcomed me with this blank popup that didn't go anywhere and had to relaunch the Finder.

Any idea how to fix this and have Virtual files working on macOS?
If needed, I can troubleshoot on an Intel Mac Pro or ARM MacBook Pro; both are running macOS 15.3.1 (24D70) Sequoia.

Steps to reproduce

1. Installed Nextcloud desktop 3.15.3 macOS Virtual files 12+
2. Connected using my server IP address
3. Skipped setting up the account
4. Enabled Enable virtual files and Enable fast sync in Settings → Virtual file sync
5. Scanned files on the server
6. Locations → Nextcloud is empty, keeps loading

Expected behavior

When enabling Virtual files and after it finished scanning files, it should appear in Locations → Nextcloud on macOS

Which files are affected by this bug

All

Operating system

macOS

Which version of the operating system you are running.

macOS 15.3.1 (24D70) Sequoia

Package

Official macOS 12+ universal pkg

Nextcloud Server version

31.0.0

Nextcloud Desktop Client version

3.15.3

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

Fresh desktop client install

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

Additional info

Anonymised Nextcloud desktop debug archive:
2025-03-06_nextcloud-debug-archive.zip

[buiapp]

VFS also doesn't work for me on MacOS 15.3.1. But I get an error message when clicking on the Location entry:

You can’t open the application “Nextcloud-45cde930008fce46ad077d23c8e7d6c@nextcloud.abc.abc” because it may be damaged or incomplete.

[nilsding]

@buiapp the issue you're facing has been fixed with #7835 and will be part of the next release 3.16.0 (assuming the domain of your Nextcloud instance ends in .app)

as for OP's issue, I wonder if #7768 resolved this too (that PR is also part of 3.16.0)

[buiapp]

Wow, that's a very niche bug I tapped into. 😅 Just because of the .app domain...

[sjg2203]

I sometimes have this bug #7768 on my Intel macOS after a reboot, but never on my ARM macOS.
I tried with Nextcloud 3.16.0-rc2, as I could not find rc3 on this site, same empty Finder with loading wheel appears.

as for OP's issue, I wonder if #7768 resolved this too (that PR is also part of 3.16.0)

[nilsding]

@sjg2203 hmm, interesting that the architecture matters there. 🤔

Regarding this issue you've opened -- does that occur on both Intel and ARM?

[sjg2203]

Got this issue on both Intel and ARM, on both I had 3.15.3. I updated my ARM macOS to 3.16.0-rc2, same issue with it.
However, in 3.16.0-rc2, the pause icon is no longer shown and is replaced by the sync icon, even though it says 'All synced!'

@sjg2203 hmm, interesting that the architecture matters there. 🤔

Regarding this issue you've opened -- does that occur on both Intel and ARM?

[buiapp]

@nilsding My Mac client still crashes even with the newest version 16.0. I attached a console log that could help troubleshoot.

It crashes only when I use the Nextcloud VFS client. The normal client works as expected.

nextcloud.log

20250310_1411_nextcloud.log

[sjg2203]

@nilsding I updated to Nextcloud 3.16.0, rebooted my Mac, still no change.

I played around a bit and found that some people had to add showExperimentalOptions=true to nextcloud.cfg under /Users/youruser/Library/Preferences/Nextcloud/, though it did not help in this case.
In the same file, there is isVfsEnabled=false, I tried to switch to true but it automatically reverted to false.

As seen here, it is recommended to install notify_push, though its installation is not the most straightforward and quite buggy, I managed to have it installed and more or less running. It, however, did not help in this case.

Any idea what could cause VFS not to work? Could you guys investigate this