I am testing self-hosted owncloud (latest Docker image) with the Android app to synchronize photos off my phone. It turns out only new photos are synced automatically, so I selected all existing photos as manual uploads.
The uploading process is currently ongoing, but I see that several hundred files that are uploaded are 0 KB, and the owncloud app constantly has a notification that “An error occured in the network”.
The phone is on wifi and on the same network as the server. It’s hard to see what could be causing network errors, but obviously, something is.
When I retry the failed uploads in the app, every single file fails with “Folder error”. I’ve deleted the 0 KB files on the server and retried again, but the same thing happens.
Having gone through the first 10 files, I can see that they are all uploaded with correct file sizes reported and I can view them in the web interface. So these files are genuinely “Folder error” cases. I assume the rest are as well.
That means a question now is how all those 0 KB files failed and why they are not in the retry list.
I selected 1500+ files for upload. 953 are uploaded. 610 are now failed with “Folder error”, but seem to be present among the 953. 223 were 0 KB. None of these numbers add up…
I take it from what you’re writing that a failed upload is assumed to cause the same issue as a cancelled upload, resulting in files with 0B.
If fixed, that would perhaps alleviate the failure situation, since I would know that a file was either properly uploaded or not, but I’m not entirely sure it helps me advance. I was easily able to delete all 0B files. The real issue here is I don’t know which files became 0B files. Deleting the 0B files and then retrying all files in the retry list didn’t help, so apparently the 0B files weren’t in the retry list, which I think they should have been?
Also, again, there’s no apparent reason for network errors. I did notice the app was starting a large number of simultanous uploads. Perhaps there is a concurrency issue in the app or the server?
The duplicate upload issue you’ve linked to seems to be related to automatic uploads, whereas I was doing a manual upload. Also, there was no mention of “(1)” being added to the filename. The underlying issue might be same – I wouldn’t know. Fingers crossed one fix fixes both.
We detected the duplicate upload issue also happens with manual uploads, not only with automatic uploads, so it could be the same problem underneath.
From the outside, there is no apparent reason for network errors, but they happen. We would like to research on the problem, and logs would be very helpful (for both issues). Would you like to provide some of them? Just enable them in “Settings > Logging > Enable logging” and check “Log HTTP requests and responses” so that network calls are included here. You can send them to android-app@owncloud.com and we’ll take a look .
. Any other question just ask! 
Fingers crossed one fix fixes both.
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