Dropbox error 400

I have two macs and a DevonThink database on each. I sync the databases via dropbox. I’ve not had any sync issues.

I am retiring one of my macs so I moved its database over to the new mac.

I ran into a problem when I attempted to set up sync via dropbox on the new mac. I selected “Add Dropbox Sync Store” and gave the sync the same name and p/w as I’d been using before the move.

When I click on “OK,” it returns the error “Error while setting up location [Nameofsync].dtCloud dropbox.com 400”

Searching dropbox’s help files, I found the error 400 has something to do with the name of the file. I tried renaming the file, but I get the same error.

I have no idea how to fix this problem. Am I setting up my new mac correctly?

Thanks in advance.

Which version of DEVONthink and of macOS do you use? Does it also fail when creating a second Dropbox sync store? Which name did you actually use?

DevonThink version = 3.7.3
Mac OS version = 11.3.1

The sync sore name is JeffsDevonThinkSync. I’ve tried using different name, but each time I get the same “Dropbox 400” error.

The current public release is actually 3.7.2 and the latest release of Big Sur is 11.5.1.

There shouldn’t be any filename issue as our sync engine isn’t sending files as you see them in the database. The filenames sync sends are constructed to work with Dropbox.

Have you checked the amount of space you have available in your Dropbox account?

My apologies. My DevonThink version is indeed 3.7.2. I’ve updated my mac to version 11.5.1

I still get the same error as before.

I am using less than 2% of my Dropbox account.

Do you have more than one Dropbox account?

No, I just have the one account.

Assuming you’re running the Dropbox application, have you disabled syncing the Apps/DEVONthink Packet Sync folder in Dropbox’s preferences?

Yes, this has been done, but the problem persists.

Does the issue persist after rebooting the Mac?



Does DEVONthink have Full Disk Access and all its Automation requests allowed (if any) in System Preferences > Security & Privacy > Privacy ?

Yes, both Dropbox and DevonThink have “Full Disk Access.”