Not renaming .tmp files in Win10

[Fred1 (Fred)]

Two computers named ComputerA and ComputerB, both running Windows 10. Both running on a LAN. Normal Windows file sharing is working correctly.

Both running portable Syncthing v1.18.6 with SyncTrayzor v1.1.29. No problems with the computers communicating, nor Syncthing connecting them, nor ComputerA shared folder (“FolderA”) being setup on ComputerB.

Files on ComputerA are placed into FolderA. ComputerB detects out-of-sync. Files are copied as .tmp files to ComputerB but the Syncthing cannot rename them:

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[55S57] 17:57:00 INFO: Puller (folder “FolderA” (dymfc-mpjar), item “Doc1.odt”): syncing: rename \?\C:\Users\ComputerB\Documents\SyncThing\FolderA~syncthing~Doc1.odt.tmp \?\C:\Users\ComputerB\Documents\SyncThing\FolderA\Doc1.odt: Access is denied.

[55S57] 17:57:00 INFO: Puller (folder “FolderA” (dymfc-mpjar), item “Doc1.pdf”): syncing: rename \?\C:\Users\ComputerB\Documents\SyncThing\FolderA~syncthing~Doc1.pdf.tmp \?\C:\Users\ComputerB\Documents\SyncThing\FolderA\Doc1.pdf: Access is denied.

[55S57] 17:57:00 INFO: “FolderA” (dymfc-mpjar): Failed to sync 2 items

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Permissions on the folder and files are thoroughly correct - SYSTEM, ComputerB, Administrators all have Full control. (Just for good measure, I added “Everyone” with the same rights on both computers’ files and folder.)

A similar topic from last month (“not syncing only creating tmp files”) was never resolved. That one seemed to have a Google Drive issue in it. There is no Google Drive / Google Sync on my machines.

[AudriusButkevicius]

This is just an error we get from the operating system that we propagate to you.

We don’t know/can’t tell you why that happens.

As I said, usual suspect is permissions/ACLs/files being locked by something.

I’d also transfer ownership of those files to the user running syncthing.

There is not much we can help you here other than telling you “figure out why your OS doesn’t allow that”.

[AudriusButkevicius]

Also, user directories in windows are special, I think you need admin perms to modify other users files, so you should probably run this as ComputerB user or Admin.

[Fred1 (Fred)]

For some reason I didn’t think of this until later. The problem was the antivirus. It has a “ransomware protection” feature that apparently was preventing apps from renaming files. Even apps which I had explicitly told it to ignore, and on folders which it was also told to ignore. After struggling with it for awhile I ended up having to turn off the ransomware protection to allow Syncthing to work correctly.