We had a bad experience few days ago: one of the Windows clients started deleting files on a shared folder on its own!
Unfortunately we were not able to capture the log on the client because it has been deleted by the user who uninstalled Nextcloud in fear.
On the server side we cannot understand what happened on the client. On the webserver log and in nextcloud.log we can only passively see the actual actions performed, so it’s kind of troublesome.
By talking to the user of the computer which misbehaved they can only tell they were working normally when one of the software complained disk C was full. While Nextcloud data directory is on D my only guess is that the client’s SQlite DB got corrupted so it started doing things on its own.
I understand it’s hard this way but at this time this is the only way we can figure it out. I hope someone with knowledge of the Windows client can tell if this is possible or if there can be any other reason.
Client was 3.0.1 (now upgraded to .3).