This application's locale, en_US, is not supported by all of its localization delegates.

[horo99]

Warning: This application's locale, en_US, is not supported by all of its localization delegates.

• A FluentLocalizations delegate that supports the en_US locale was not found.

The declared supported locales for this app are: en_US

---

the version i'm using is 3.12.0

[horo99]

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return FluentApp.router(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        accentColor: Colors.blue,
        brightness: Brightness.dark,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      localeResolutionCallback: (locale, supported) {
        return const Locale('en', 'US');
      },
      localizationsDelegates: [
        GlobalWidgetsLocalizations.delegate,
        GlobalMaterialLocalizations.delegate,
        GlobalCupertinoLocalizations.delegate,
        LocalJsonLocalization.delegate,
      ],
      supportedLocales: const [
        Locale('en', 'US'),
      ],
      routerDelegate: Modular.routerDelegate,
      routeInformationParser: Modular.routeInformationParser,
      color: Colors.blue,
    );
  }
}

[bdlukaa]

You must add DefaultFluentLocalizations to localizationDelegates

[horo99]

You must add DefaultFluentLocalizations to localizationDelegates

Thans for your timely reply, but it didn't work.

After adding countryCode: 'US' like below, the warning disappeared.

In file localization.dart, maybe the implement of support method needs to be refined.

  static bool supports(Locale locale) {
    return S.delegate.supportedLocales.contains(locale);
  }

[bdlukaa]

Reproducible.

Logs:

══╡ EXCEPTION CAUGHT BY WIDGETS ╞═══════════════════════════════════════════════════════════════════
The following message was thrown:
Warning: This application's locale, en_US, is not supported by all of its localization delegates.

• A FluentLocalizations delegate that supports the en_US locale was not found.

The declared supported locales for this app are: en_US

See https://flutter.dev/tutorials/internationalization/ for more information about configuring an
app's locale, supportedLocales, and localizationsDelegates parameters.
════════════════════════════════════════════════════════════════════════════════════════════════════

Another exception was thrown: No FluentLocalizations found.