Certain addons have always been added to your project in the past, these could not be uninstalled or manually configured through the Divio Cloud interface.
With the release of django CMS 3.4.0 (LTS) we changed this behaviour. Now you can uninstall for example django CMS Link and use the link plugin provided by django CMS Bootstrap 3 instead to prevent multiple link choices in the user interface.
To upgrade your project to 3.4 on Divio Cloud, simply install these addons first from the "Addons" section:
In addition, make sure other addons, such as the essentials (news & blog, people, events, jobs, faq) are updated to their latest version.
After installing the above mentioned addons, upgrade to django CMS 3.4 and deploy your website.
Be aware that removing some addons, such as django Filer or CKEditor might have unwanted side-effects, as several other addons depend on them.