Localization bug?

Just as I’m about to finalize a new version of my app, I suddenly noticed that it no longer localizes as it used to. My app is localised to 5 languages, using dynamic constants, and it used to work flawlessly. Not so anymore; Even though my system is set to danish, my app now only runs in english, both in the debugger and compiled.
Have I unchecked a checkmark somewhere - is there a bug in 2016 r1, or could it be something introduced with macOS Sierra? Anyone else experiencing the same?

Did you move pieces of code that contain the localizations to external files? I had the feeling there is a problem somewhere but did not look into it deeper.

Make sure the ‘Dynamic’ flag is checked for all dynamic constants.

If that’s the case already, try setting the Language in the Build settings to the same as the default language of your dynamic constants.

So if the Default language of your dynamic constants is English, go to Build Settings -> Shared -> Language and set it to English.

Thanks Marco. The default language was set to “default”. Setting it to “English” did the trick.

…now back to testing…