I’ve had a couple of clients with a Synology syncing to Dropbox via Cloud Sync and after Dropbox upgraded their tenancy to use the new Dropbox Team Space, syncing stopped, and it couldn’t be set up again.

When you remove the sync task from Cloud Sync, you can set up a new task with Dropbox Team Space instead of just Dropbox, but it simply doesn’t work.

For some unknown reason, the latest Cloud Sync package that DSM seems to want to automatically update to is (as of 24 May 2024) 2.6.2 and this version does not work.

The solution is to go to the Download Centre for your particular NAS, browse the list of packages there and manually download the latest package for Cloud Sync. In my case, I was able to download version 2.7.0 and install it. Once I had upgraded to 2.7.0, I was then able to successfully set up a Dropbox Team Space sync task and resync the NAS with all of the folders in the cloud.