MissingPluginException(No implementation found for method configure on channel com.amazonaws.amplify/amplify)

Question

When running the Amplify Flutter tutorial project after configuring the authentication plugin, I constantly receive the following error:

Error: MissingPluginException(No implementation found for method configure on channel com.amazonaws.amplify/amplify)
    at Object.throw_ [as throw] (http://localhost:56261/dart_sdk.js:5331:11)
    at MethodChannel._invokeMethod (http://localhost:56261/packages/flutter/src/services/system_channels.dart.lib.js:954:21)
    at _invokeMethod.next (<anonymous>)
    at http://localhost:56261/dart_sdk.js:39029:33
    at _RootZone.runUnary (http://localhost:56261/dart_sdk.js:38886:58)
    at _FutureListener.thenAwait.handleValue (http://localhost:56261/dart_sdk.js:33872:29)
    at handleValueCallback (http://localhost:56261/dart_sdk.js:34432:49)
    at Function._propagateToListeners (http://localhost:56261/dart_sdk.js:34470:17)
    at _Future.new.[_completeWithValue] (http://localhost:56261/dart_sdk.js:34312:23)
    at async._AsyncCallbackEntry.new.callback (http://localhost:56261/dart_sdk.js:34335:35)
    at Object._microtaskLoop (http://localhost:56261/dart_sdk.js:39173:13)
    at _startMicrotaskLoop (http://localhost:56261/dart_sdk.js:39179:13)
    at http://localhost:56261/dart_sdk.js:34686:9

The code below in main.dart is copied directly from the Amplify Flutter, but using only the Auth plugin:

class _MyHomePageState extends State<MyHomePage> {
  @override
  initState() {
    super.initState();
    _configureAmplify();
  }

  void _configureAmplify() async {
    AmplifyAuthCognito authPlugin = AmplifyAuthCognito();
    Amplify.addPlugin(authPlugin);

    try {
      await Amplify.configure(amplifyconfig); # <--- this is what throws the MissingPluginException 
    } on AmplifyAlreadyConfiguredException {
      print(
          "Tried to reconfigure Amplify; this can occur when your app restarts on Android.");
    }
  }
...
}

pubspec.yaml:

name: <myproject>
description: <description>

version: 1.0.0+1

environment:
  sdk: ">=2.7.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter

  amplify_flutter: '<1.0.0'
  amplify_auth_cognito: '<1.0.0'

  cupertino_icons: ^1.0.2

dev_dependencies:
  flutter_test:
    sdk: flutter

flutter:
  uses-material-design: true

Yeah, yeah, I've already searched stackoverflow and github. I've tried everything anyone's suggested including:

• shut down the app, run flutter clean then flutter pub get
• updating all my dependencies
• Invalidated caches & restarted Android Studio
• ensured widgets are initialized by calling WidgetsFlutterBinding.ensureInitialized() in main()
• ensured I'm not calling Amplify.configure() before the Auth plugin is loaded
• started a completely new project and reinitialized Amplify

Answer 1

As of posting, Amplify-Flutter does not support the Web platform, and this error is expected behavior until then. See: https://github.com/aws-amplify/amplify-flutter/issues/234