Until now, free Dropbox Basic Account users have been able to link an unlimited number of devices to their accounts. However, Dropbox is changing how linking works for free accounts and is now limiting this number to just three devices, as pointed out by Slash Gear.
Dropbox Plus and Dropbox Premium users will still be able to link an unlimited number of devices with their account.
Basic Account users, who have reached their device limit, can change which three devices are linked to their account by first unlinking devices they don’t want on their account down to less than three, and then link the devices that they want.
Alternatively, when you install the Dropbox app on a new device, you will be given a list of older devices that you can remove from the three slots, taking up one of their places with the new installation.
Dropbox notes that for Basic users who have linked more than three devices prior to March 2019, all of their previously linked devices will remain linked, but they won’t be able to link additional devices.
Visit this link to learn more about linked Dropbox devices.