As of version 2.3.16 of the KunstmaanAdminBundle, it is possible for the admin users to choose their preferred admin interface language. In the previous versions, the admin interface language was always the same as the site language the user was editing. This was not really desired behaviour, so we made content input in foreign languages more user friendly by only using the preferred admin interface language on all pages.
To configure the default and available admin interface languages, you need to add the snippet below to your config.yml:
kuma_admin: default_admin_locale: en admin_locales: ['nl', 'fr', 'en']
When you upgrade the Kunstmaan Bundles, you need to update your database to add the new column in the kuma_users table. By default, all users will see the admin interface in English.