Why Doesn't Dropbox Syncing Work
If you're an existing 1Password user and store your data in the Dropbox folder then 1Password should automatically find it and start using it when you install 1Password from the Mac App Store.
Note: If you're receiving an error message while trying to sync with your mobile devices, please read this article instead.
The only exception is when your Dropbox folder is not in its default location in your home folder:
[Your Home Folder] > Dropbox
Using this location is very important because of the sandboxing restrictions enforced by the Mac App Store. Since 1Password 3.9 is properly sandboxed as per Mac App Store requirements, you can only use Dropbox if it's folder is in the default location.
This also applies to new 1Password users, if your Dropbox folder is not in the default location then you'll see the 'Use Dropbox' option is greyed out and as such won't be able to sync 1Password with Dropbox until you move your Dropbox folder back to the default location.
To change your Dropbox folder back to it's default location, see the official documentation from Dropbox: How do I move my Dropbox folder to a new location?. When setting the Dropbox location, select the item with the Home icon, as shown here:
