The document claims that it’s being blocked by another device even though the devices aren’t currently syncing. My other device is at home, which is nowhere near me, and it’s off.
So I choose to edit the document anyway.
I go home with the newer version of the document and try to sync between devices.
The devices fail to sync the folder where the file was edited.
I restart syncthing on both devices but the issue persists.
This is the second time it’s happened out of two times and I want a proper fix. I can’t deal with this every single time. The folders are both send and receive and they aren’t connected whilst I’m editing the document. What could possibly be the issue?
2026-03-31 09:12:56 INF Deleted file (folder.label=Documents folder.id=epgof-qruhw folder.type=sendreceive file.name=“DOCUMENT#” log.pkg=model)
2026-03-31 09:12:56 WRN Failed to sync (path=“DOCUMENT” error=“syncing: finishing: moving for conflict: removing item to be replaced: simple versioner: archive: remove \\?\C:\DOCUMENT: The process cannot access the file because it is being used by another process.” folder.label=Documents folder.id=epgof-qruhw folder.type=sendreceive log.pkg=model)
2026-03-31 09:12:56 INF Folder failed to sync, will be retried (wait=1m0s folder.label=Documents folder.id=epgof-qruhw folder.type=sendreceive log.pkg=model)
2026-03-31 09:17:04 INF Completed initial scan (folder.label=Documents folder.id=epgof-qruhw folder.type=sendreceive log.pkg=model)
2026-03-31 09:17:04 WRN Failed to sync (path=“DOCUMENT” error=“syncing: no connected device has the required version of this file” folder.label=Documents folder.id=epgof-qruhw folder.type=sendreceive log.pkg=model)
2026-03-31 09:17:04 INF Folder failed to sync, will be retried (wait=1m0s folder.label=Documents folder.id=epgof-qruhw folder.type=sendreceive log.pkg=model)
I’ve replaced the private folder and documents names in question with “DOCUMENT”.
2026-03-31 12:01:53 WRN Failed to sync (path=“Works\Written Works\Book of Health\Summary of Nutrition v2.odt” error=“syncing: finishing: moving for conflict: removing item to be replaced: simple versioner: archive: remove \\?\C:\DOCUMENT: The process cannot access the file because it is being used by another process.” folder.label=Documents folder.id=epgof-qruhw folder.type=sendreceive log.pkg=model)
I think I might have found what the problem is. The device that I keep at home (Device A) had the document already open. And, crucially, it was open in edit mode. I had been editing the document and it remained open and in that mode when I did the initial sync, because I always keep it open on A. So it synced with my other device (Device B) just fine at first, but it had synced with the knowledge that the document was currently in edit mode on A. So when I took out B and edited the document away from home, that’s why it warned me that another device was preventing other ediits of the document. And when I took B back home to sync with A, the old document was still open in edit mode on A, thus blocking the sync since it won’t sync if one device has the file open in edit mode and the other file has a different edited version. It’s a conflict and it blocks the sync.
Solution: Always keep editable documents closed (or at least out of edit mode) on both devices before you sync. Sheesh
Syncthing has no such facility to “block by another device” So some other process is interfering here. Is it a OneDrive folder? Google Drive folder, or some other file sharing type file?
Maybe as you say when the file is open on one device the system creates a “lock file” which is also synced by syncthing.
Anyway the point is syncthing doesn’t “lock” any files. Depending how other processes lock files, syncthing may or may not synchronize the lock state of the file with other devices.
Pretty sure libreoffice writer is creating lock files which are also synchronized by syncthing. So the lock state is also synced.
So yes you need to close the file on one system before you edit on the other.
you could also possibly exclude the lock files from syncing, but then you risk sync conflicts if the files are edited on different machines at the same time. (Or if libreoffice is changing the file contents during open or close even if no edits are done.)