Help Wanted: Problems with German Locale

[JHarzenetter]

I'm running into this issue with the German localisation.

My Root Node looks like this, as mentioned in the Docs.

MaterialApp(
      title: ....,
      supportedLocales: flc.CountryLocalizations.supportedLocales.map(Locale.new),
      localizationsDelegates: const [
        flc.CountryLocalizations.delegate,
      ],
      home: FutureBuilder(...)

My device language is set to german and after the start I get following error message:

======== Exception caught by widgets ===============================================================
The following message was thrown:
Warning: This application's locale, de, is not supported by all of its localization delegates.

• A MaterialLocalizations delegate that supports the de locale was not found.
• A CupertinoLocalizations delegate that supports the de locale was not found.

The declared supported locales for this app are: en, af, am, ar, az, be, bg, bn, bs, ca, cs, da, de, el, es, et, fa, fi, fr, gl, ha, he, hi, hr, hu, hy, id, is, it, ja, ka, kk, km, ko, ku, ky, lt, lv, mk, ml, mn, ms, my, nb, nl, nn, no, pl, ps, pt, ro, ru, sd, sk, sl, so, sq, sr, sv, ta, tg, th, tk, tr, tt, uk, ug, ur, uz, vi, zh

Version of the library: 0.1.9+1

Obviously the locale 'de' can be found in the list but it doesnt work.

If I set the system language to english everything works fine.

Any Ideas?