Maybe in general, but…
Hello. I am the person trying to support original poster on the Duplicati forum. You can search for @Adramelramalech there without login to find posting history. I did the same here before feeling a need to post anything. Meanwhile I spent time trying to learn Nextcloud better than I did before it became clear that I couldn’t explain why Nextcloud (or is that actually sabre/dav?) replied like this:
System.Net.WebException: The remote server returned an error: (423) Locked.
at Duplicati.Library.Main.BackendManager.Delete
In contrast to no other Duplicati report, a Google search for “Nextcloud” “423 locked” soon led to:
File is locked - how to unlock and this seemed a good generic answer to try or take to the experts.
The initial solution seemed to be to clear locks from database. If it kept happening, move to Redis.
This issue keeps happening (see above). Would anyone like to guide user through the exact steps?
I have not used Nextcloud, am fairly good at Duplicati, but am more on the forum than on GitHub which is where the developers (wish there were more) fight coding issues. Maybe you do this too?
The backends encapsulate the actual communication with a remote host with a simple abstraction, namely that the backend can perform 4 operations: GET, PUT, LIST, DELETE. All operations performed by Duplicati relies on only these operations, enabling almost any storage to be implemented as a destination.
What this means is that nothing fancy such as any WEBDAV file locking is tried, as far as I know.
Transactional file locking seems like something different. and manual says default uses database.
https://github.com/duplicati/duplicati/blob/master/Duplicati/Library/Backend/WEBDAV/WEBDAV.cs
if anyone wants a look. I’m not a C# developer but have done enough other coding to get an idea.
I can speak in general terms, but getting details on this specific problem has been hard (like here).