You may receive the following error message when attempting to join or leave a Dropbox Business team:
To update to your new plan, Dropbox needs to sync your files again, which might take a while. Your current files will be saved in Dropbox (Old).
If you receive this error message, your files are safe, but Dropbox needs to re-sync them.
First, Dropbox renames your current folder to Dropbox (Old).
Then, Dropbox creates a new folder in the same location on your computer and re-syncs your files to it from your account.
The result is two folders. This process is just a precaution to ensure that a copy of your files are safe on your computer while your files are re-syncing. We recommend not updating the Dropbox (Old) folder while the re-sync is taking place, so you can delete it after the re-sync and not lose any changes.