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

[adasiewiczr]

Describe the bug
Application crashes on Android when trying to configure Amplify with the following error:

E/flutter (15062): [ERROR:flutter/lib/ui/ui_dart_state.cc(166)] Unhandled Exception: MissingPluginException(No implementation found for method configure on channel com.amazonaws.amplify/core)
E/flutter (15062): #0 MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:159:7)
E/flutter (15062):
E/flutter (15062): #1 MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:334:12)
E/flutter (15062): #2 MethodChannelAmplifyCore.configure (package:amplify_core_plugin_interface/method_channel_amplify.dart:25:21)
E/flutter (15062): #3 Amplify.configure (package:amplify_core/amplify_core.dart:71:35)

To Reproduce
Steps to reproduce the behavior:

1. Configure Amplify with AmplifyAuthCognito plugin
   final amplifyInstance = Amplify(); final authPlugin = AmplifyAuthCognito(); await amplifyInstance.addPlugin(authPlugins: [authPlugin]); await amplifyInstance.configure(amplifyconfig);
2. Application crashes

Platform
Amplify Flutter current supports iOS and Android. This issue is reproducable in (check all that apply):
[x] Android
[] iOS

Flutter 1.20.2 • channel stable • https://github.com/flutter/flutter.git
Framework • revision bbfbf1770c (4 weeks ago) • 2020-08-13 08:33:09 -0700
Engine • revision 9d5b21729f
Tools • Dart 2.9.1

[fjnoyp]

Hi @adasiewiczr did you setup Auth with the Amplify CLI?

[adasiewiczr]

@fjnoyp I've provided configuration manually. It seems that for some reason plugin isn't registered

[fjnoyp]

Hi @adasiewiczr

If you add a plugin (like Auth) without configuring it properly in amplifyconfiguration.dart, the configure step can cause crashes like in your case.

When creating your amplifyconfiguration.dart file, did you follow the instructions here?
https://docs.amplify.aws/lib/auth/existing-resources/q/platform/flutter

Also, can you do a "flutter clean" before rerunning your application?

[adasiewiczr]

Hi @fjnoyp
yes, I followed those instructions and I tried to run flutter clean before rerunning the app and it doesn't change anything :(
Here you can find my config file:

const amplifyconfig = '''{
"auth": {
"plugins": {
"awsCognitoAuthPlugin": {
"IdentityManager": {
"Default": {}
},
"CognitoUserPool": {
"Default": {
"PoolId": "ap-xxxxx,
"AppClientId": “xxxxx”,
"Region": "ap-xxxx”
}
},
"Auth": {
"Default": {
"authenticationFlowType": "USER_PASSWORD_AUTH"
}
}
}
}
}
}''';

[adasiewiczr]

@fjnoyp I've resolved the problem so the issue can be closed. I found out that my project was using an old Android wrapper and I had to migrate it to the newer version - https://github.com/flutter/flutter/wiki/Upgrading-pre-1.12-Android-projects

[fjnoyp]

Hi @adasiewiczr thanks for sharing that with us. We'll update our documentation to help other users that might encounter this problem as well.