FlutterFirebaseCorePlugin.java uses or overrides a deprecated API

Seems it is a bug in Firebase plugins: https://github.com/FirebaseExtended/flutterfire/issues/3876. However setting min SDK to 23 does not show the warning.

it worked for me to change my sdkVersion to 23:

just go to android>app>build.gradle and change the minSdkVersion-line in defaultConfig{} to .. minSdkVersion 23

$ flutter pub get

Just Do it in your Terminal it will work

I was having the same problem today and I found the solution here on Github

First, get the latest versions of your dependencies from pub.dev

Current latest versions are these:

1. firebase_auth: ^0.20.0+1
2. firebase_core: ^0.7.0

Then run these 3 commands in the terminal:

$ flutter pub upgrade

$ flutter pub get

$ flutter clean

And then run your project

$ flutter run

This will hopefully help you.