Server files deleted after updating Windows client to 4.0.3

I use a Nextcloud folder as the data server for jellyfin. For that, I’ve set

'localstorage.umask' => 2

in config/config.php, added the user “jellyfin” to the group “www-data” and regularly scan the folder for new files, so they can properly sync (I’ve set jellyfin to write the metadata for videos in the folder the video is saved in). I’m using the virtual file system on my windows, because I don’t need the files locally, but still need to see the structure for uploads. This worked flawlessly, until today.

I updated my windows client to 4.0.3. Every single file in my videos folder got the “Couldn’t update placeholder info”. Then, it seems to have initiated the deletion of all files in that folder. Once I noticed, I stopped the sync and restored, but I’m afraid the deletion starts again once I enable sync on windows.

Any idea what I can do here? Reverted to 4.0.2, working as expected again.

I’m running 31.0.11 on the server.

similar topics exist

many Github issues exist e.g. https://github.com/nextcloud/desktop/issues/3444 created myself but all this reports dead-ended as it’s really hard to reproduce.. Please collect logs, eventlog and each possible detail and file a new bug so devs are aware the problem sill exists.

Please provide this as references: