The root cause is that Dropbox sync and iCloud sync, such as that in the Optimized Storage feature of Sierra, remain incompatible.

Dropbox uses Accessibility for the Dropbox badge, part of its integration with Microsoft Office. When installing Dropbox, give access to Dropbox to Accessibility when asked.Don’t use “symlinks” (presumably any type of alias) in your Dropbox, particularly those which might point to files or folders in the Desktop or Documents folder.I presume this would only occur if you are also using iCloud syncing as well as Dropbox. If you’re taking screenshots, avoid turning Dropbox off, or those shots may be replaced by iCloud placeholder files and then synced to Dropbox when it is enabled again.Don’t rename your Dropbox folder leave it named simply as Dropbox.You should avoid using any configuration in which iCloud and Dropbox might synchronise the same files.You should avoid using any settings which might move files from your Desktop or Documents folder to iCloud storage (see below).

You should leave Dropbox in its default location, and not move it to the Desktop or Documents folder.

You should ensure that you have updated to 10.12.1 (although nowhere does the support article even mention that update, as it was written before its release, and has not been updated in the light of it).

To use Dropbox safely when you are running macOS Sierra:

Dropbox still works, but it is still possible to use it in a way which is likely to result in data loss, according to its own support article. This article examines how those issues with Dropbox have been resolved.Īlthough updated versions of the Dropbox desktop app have been released since September, Dropbox’s detailed advice to users has changed little over much of that time. When macOS Sierra was released over two months ago, there were two serious conflicts which could, and did, result in loss of data: with Fujitsu ScanSnap software, which has now been fixed, and with Dropbox.

Dropbox desktop app will not update