Firebase issue "Flutter NSException: Configuration fails. It may be caused by an invalid GOOGLE_APP_ID in GoogleService-Info.plist or set in the customized options

[Farial-mahmod]

We have configured Firebase settings as needed mentioned in the Firebase docs and GoogleService-info.plist file does already have the IDs . The app runs smoothly in Android devices but stops during the initial splash on iOS simulator device each time. There is no other errors in the log / run . Ours is the latest Flutter, Dart and MacOS Monterey versions - all are up-to-date .

We have already tried clean-build, replacing iOS-Firebase files, fechanique/cordova-plugin-fcm#308 and https://stackoverflow.com/questions/62787686/flutter-nsexception-configuration-fails-it-may-be-caused-by-an-invalid-google but none of these old solutions work.

Your help would be appreciated .