From the Engine Desktop, The Dropbox files are synced using Sync Manager.
I have Prime 4+ on Latest 3.2 Version of Engine DJ Software. I am not using SSD or SD Card, I am using USB Sticks in the Slot 1. I have linked the Dropbox account using the hardware code.
I am able to see Dropbox as Source, when I click on the Dropbox source it says checking database and then Hangs, it never comes back with the list of songs.