Windows Client doesnt sync virtual files

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Nextcloud version (eg, 20.0.5):
Operating system and version (eg, Ubuntu 20.04): 22.04.3 LTS
Apache or nginx version (eg, Apache 2.4.25): nginx 1.25.3
PHP version (eg, 7.4): PHP 8.1.2
Windows: Edition: Windows 10 Business, Version: 22H2, Build: 19045.3448, Windows Feature Experience Pack 1000.19044.1000.0

The issue you are facing:

from one day to other the nextcloud windows application stopped syncing. the applications hangs. changing sync from virtuial to download files works and files are synced. But with virtual file windows app seems to check files on server and after that when it should created the files the app hangs. this problem is on all our windows 10 company clients. Nothings helps: app reinstalled; app completly removed with all folders like nextcloud, local-nextcloud, roamin-nextcloud and fresh install; removing all windows updates and reinstalled.

On an fresh installed windows pc with actual windows updates the sync/download with virtual files works.

so something like windows updates, or other windows settings brings the app to hang while syncing virtual files.

do you have any hints / ideas why nextcloud applications hangs on windows while syncing virtual files??

Is this the first time you’ve seen this error? (Y/N): Y

Steps to replicate it:

  1. problem on all company workstation - don’t know how it can be reproduces

The output of your Nextcloud log in Admin > Logging:

No errors shown

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

not relevant, problem is not on server about configuration. problem is on the windows client.

The output of your Apache/nginx/system log in /var/log/____:

not relevant

Output errors in nextcloud.log in /var/www/ or as admin user in top right menu, filtering for errors. Use a pastebin service if necessary.

not relevant

Hi, I’m experiencing the same problem.

Nextcloud version: 27.1.3
Windows Client: 3.10.1
Windows Edition: Windows 2022 Server (Terminal Server with 20+ Users)

VFS worked 3 days ago. Now syncing only works when disabling VFS (3800 files). With VFS on the client freezes and goes offline after a while. Maybe it gets a timeout. Sometimes it goes into the state “waiting to start sync” forever.

UPDATE: I reverted back to Client 3.9.0, the one which worked on first install. This Version also doesn’t work anymore. The client scans for changes and freezes on the first file to sync (2 kb). Windows kills the process after some time, the explorer is unusable during this time. Syncing an account with 2 files and VFS behaves the same. Seems like the problem is Windows related. Maybe an update which broke VFS?

Did you already try to disable network upload- and download limitations?

Then you can try disabling apps, one by one, maybe there is an app that causes problems. I have read somebody could solve his problem by disabling circles app.

You can check the sync log to see if there are problems with a specific file.

Much luck,

Hi ernolf,

thanks for taking your time. I do not think disabling apps would lead to success as syncing with VFS off is working perfectly.

I tried it with an account which has only 3 files. The Client freezes restarts several times an finally gets a successful sync. Windows explorer is unusable during this time.

Here is the log, I changed Server and Usernames. Appdata folders were deleted before. 2023-11-06 09:17:53:518 [ info nextcloud.gui.application C:\Users\sysadmin\AppDa -

Hi all,

it seems really to be Windows related - because we installed a new PC in the office with Windows (same build) and on it all works fine. So it is also the same network. So it can’t be a problem with apps or network limitation (don’t have any).

But on several other company PCs the app hangs on the first virtual file.

I uninstalled all Windows Updates on the affected PC, but no difference.

In the nextcloud windows app i found “Using virtual files plugin: wincfapi” so i searched for it in the web.

So I read some older bugs and problems about C:\windows\System32\cldapi.dll

On the working PC it is version 10.0.19041.3570 and on the affected PC version 10.0.19041.3393.

But copying the file from working PC to affected PC doesn’t change anything.

Do anybody know wich other DLL or Windowsw files are used for creating virtual files??

Since yesterday the client is syncing correctly again. The weird thing is that I didn’t do anything. I found out while configuring the client for a new user and synced. Now it’s working for all other users again. :thinking:

Thank you for information. I checked today on our systems and the client works also again without problems. We haven’t changed nothing, nor on server side nor the Nextcloud Windows-App. I can’t also see any Windows Updates or changes. So the problem seems to be solved. But WTF what was it?

The last Windows Update on the terminal server was on October 16th. The client is v3.9. No changes were made on the client system or Nextcloud. I really don’t know what is going on here.

I had the same problems with hanging sync with virtual files since somewhen in october. So I switched the account in the client to sync without virtual files, which was working without a problem.
Since I read this discussion I have nothing changed until now: Switched on the use of virtual files, and it works.
I’m really wondering whats going on here.