MP4 files occasionally become corrupted when synced from QNAP HBS3 to Dropbox

Question

I am using QNAP NAS with Hybrid Backup Sync (HBS3) to perform two-way synchronization between the NAS and Dropbox.

Occasionally, an MP4 file uploaded from the NAS to Dropbox becomes corrupted.

The situation is as follows:

* The original file on the NAS plays normally.
* HBS3 reports that the synchronization completed successfully.
* However, the file on Dropbox is smaller than the original file and cannot be played correctly.
* If I run the synchronization again for the same file, the file becomes normal.

In one previous case, the original file on the NAS was approximately 1.11 MB, while the file on Dropbox was only approximately 312 KB.

Following instructions from QNAP Support, I updated HBS3 and recreated the synchronization job with the same settings. After doing so, the problem did not occur for some time, but recently the same issue occurred again.

Has anyone experienced a similar issue where HBS3 reports a successful synchronization, but the file on Dropbox appears to have been only partially uploaded?

Could this possibly be related to a Dropbox-side issue, or is there anything I should check on the Dropbox side?

Any information or suggestions would be greatly appreciated.

Thank you.

Hannah · Answer

Hi there, @Ts_ka, thanks for your reply!

To see if your files synced successfully on the Dropbox desktop app, you'll need to click on your Dropbox icon first.

It will show you the sync status of the app in general, but it will also show you the sync status of individual files in your Dropbox folder, your recent syncing activity and any syncing issues you might have.

For a full log of changes to your Dropbox files in general, you can also check the events page in your account online.

If the files open as normal when uploaded directly through the Dropbox website or app, though, I'd definitely suggest looking into this from the third-party app's side, by contacting their support team.

Of course the thread will remain open in case other users have any similar experiences and have more info for you.

Ts_ka · Answer

Thank you for the suggestion.

I checked my Dropbox account, but I couldn't find any folder related to HBS3 or any other logs from the service.

Since uploading the same type of MP4 files directly through the Dropbox website works normally, is there any way to check on the Dropbox side whether an upload from HBS3 was incomplete or interrupted?

For example, is there any upload history, activity information, or other information that could help determine whether Dropbox received the complete file from HBS3?

Thank you.

Jay · Answer

There could be some logs generated by the app or service you're using, and depending on how it connects to Dropbox, there could be a special folder in which the service contains settings for your configuration, and potentially logs.

Just in case, you can try checking the generic Apps folder on your account, which should be located here if you're using a personal Dropbox account. If there is a folder there with the name of the HBS3 service, then there could be more information in there.

If you're not seeing anything, you could try searching your entire Dropbox account on the site, or alternatively, check directly on the support page for the developer of that app to see if they publish details about where logs might be kept on your account.