Years of files deleted in a desktop sync last night. Please Help

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Getting help

In order to help you as efficiently (and quickly!) as possible, please fill in as much of the below requested information as you can.

Before clicking submit: Please check if your query is already addressed via the following resources:

(Utilizing these existing resources is typically faster. It also helps reduce the load on our generous volunteers while elevating the signal to noise ratio of the forums otherwise arising from the same queries being posted repeatedly).

  • Nextcloud Server version (e.g., 29.x.x):
  • Operating system and version (e.g., Ubuntu 24.04):
    • Windows 11 / Nextcloud Desktop Client Version 33.0.4 (Windows running on windows)
  • Web server and version (e.g, Apache 2.4.25):
    • replace me
  • Is this the first time you’ve seen this error? (Yes / No):
    • yes
  • When did this problem seem to first start?
    • 3 hours ago
  • Installation method (e.g. AlO, NCP, Bare Metal/Archive, etc.)
    • AIO
  • Are you using CloudfIare, mod_security, or similar? (Yes / No)
    • Cloudflare

Summary of the issue you are facing:

I noticed a sync was going on my desktop before I went to bed. I woke this morning to see all my files from my Gopro video folder, which were set as virtual files, were all gone from my nextcloud, local files, and they are not present in my nextcloud trash or recycling bin. It says they were all deleted 3 hours ago while I was asleep.

I am terrified and downloading all the rest of the files from my cloud now. I have now idea how this could have happened, I havent changed any settings.

Even if I cant get my files back, how can I make sure this never happens again?

Steps to replicate it (hint: details matter!):

Log entries

Nextcloud

Please provide the log entries from your Nextcloud log that are generated during the time of problem (via the Copy raw option from Administration settings->Logging screen or from your nextcloud.log located in your data directory). Feel free to use a pastebin/gist service if necessary.

PASTE HERE

Web Browser

If the problem is related to the Web interface, open your browser inspector Console and Network tabs while refreshing (reloading) and reproducing the problem. Provide any relevant output/errors here that appear.

PASTE

Web server / Reverse Proxy

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

PASTE HERE

Configuration

Nextcloud

The output of occ config:list system or similar is best, but, if not possible, the contents of your config.php file from /path/to/nextcloud is fine (make sure to remove any identifiable information!):

{"reqId":"hPiWx6isXQkCk375SSYs","level":2,"time":"2026-05-25T09:12:15+00:00","remoteAddr":"108.16.128.127","user":"admin","app":"files_antivirus","method":"MOVE","url":"/remote.php/dav/uploads/admin/934531814/.file","scriptName":"/remote.php","message":"Failed to write a chunk. Check if Stream Length matches StreamMaxLength in anti virus daemon settings","userAgent":"Mozilla/5.0 (Windows) mirall/33.0.4 (build 20260504) (Nextcloud, windows-10.0.26200 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"33.0.2.2","clientReqId":"","data":{"app":"files_antivirus"},"id":"6a144672625b6"}

It would be helpful if you filled out the rest of the support template. We don’t even have your config nor app list.

The one long entry you posted indicates you’re using files_antivirus, but it’s unclear whether that transaction is related to your situation. Is it during the time window of the deletions?

What else appears in the server logs during that time?

Your Desktop client sync clients should have some clues at the start of the syncing of those files too.

Any changes to files recently in that folder?

When was the client last updated? Just trying to narrow down what’s changed or may have triggered this for you.

Also, to confirm, you are checking the Web UI when you say the files are gone, correct? Not just in the Desktop client itself.

See:

Nextcloud supports versioning.

And look in the garbage bin inside Nextcloud.