"The remote database is in use by another client"

I have a DTPO database on my desktop computer, and have just set up synching (via Dropbox) so it can sync to my laptop.

I set up synching from the desktop. Then I used a thumb-drive to copy the database to the laptop, and set up synching on the laptop. I quit DTPO on the laptop, and opened it on the desktop. The next time I hit sync on the desktop I got a message saying “The remote database is in use by another client.”

But the database is closed on the laptop. Am I doing something wrong?

Syncing needs to finish completely and clean up after itself. It is generally a good idea to wait at least five minutes after a Sync from one machine to a remote Sync has appeared to finish.