What is the problem?
I can't import or export to Dropbox anymore.
How to resolve
The Dropbox option has been removed from the app. Dropbox was facing too many issues whenever you were trying to backup your content, so we preferred to temporarily remove it from the app in order to prevent any further frustration.
At the moment, you can only import/export by email or iTunes.
Whenever Dropbox backups will be improve, then we will be able to implement it in the app again.