"Dropbox access is not authorized. Error message: v1_retired" while adding Dropbox account

[Norbert]

Steps to reproduce:
1. Install Ubuntu 16.04 LTS
2. Install `storageservicemanager` package
3. Try to add Dropbox account to it.

Actual results:
  Got this window with error message:
    Authentication Failed --- Storage Service Manager
    Dropbox access is not authorized. Error message: v1_retired

Expected results:
   Dropbox account added successfully.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: storageservicemanager 4:15.12.3-0ubuntu1.1
ProcVersionSignature: Ubuntu 4.13.0-38.43~16.04.1-generic 4.13.16
Uname: Linux 4.13.0-38-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.15
Architecture: amd64
CurrentDesktop: MATE
Date: Mon Apr 9 15:09:07 2018
InstallationDate: Installed on 2018-01-04 (94 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
SourcePackage: kdepim
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.