this is my Project Gradle dependencies
classpath 'com.android.tools.build:gradle:3.1.0'
classpath 'com.google.gms:google-services:3.0.0'
classpath "io.realm:realm-gradle-plugin:4.2.0"
classpath 'com.google.firebase:firebase-plugins:1.1.1'
this is my App Gradle dependencies
implementation 'com.google.android.gms:play-services-ads:11.4.2'
implementation 'com.google.firebase:firebase-core:11.4.2'
implementation 'com.google.android.gms:play-services-base:11.4.2'
implementation 'com.google.firebase:firebase-messaging:11.4.2'
Also i have change implementation to api ... the error still appears
add below dependency into app level gradle file ..
implementation 'com.google.android.gms:play-services-ads:15.0.1'
implementation 'com.google.firebase:firebase-core:15.0.2'
implementation 'com.google.android.gms:play-services-base:15.0.1'
implementation 'com.google.firebase:firebase-messaging:15.0.2'
You just need to change your google lib version into the stable version. you are using an unstable version. Use following
implementation 'com.google.android.gms:play-services-location:12.0.0'
implementation 'com.google.android.gms:play-services-places:12.0.0'
implementation 'com.google.firebase:firebase-messaging:12.0.0'
implementation 'com.google.firebase:firebase-core:12.0.0'
and use this classpath
classpath 'com.google.gms:google-services:3.1.1'
and remove the firebase classpath from the project
classpath 'com.google.firebase:firebase-plugins:1.1.1'
Where do you apply the google-services plugin? https://developers.google.com/android/guides/google-services-plugin#introduction requires you apply it at the bottom of your app's build.gradle to avoid dependency collisions similar to the one you are describing.
You can also run ./gradlew :app:dependencies
to see if you have any dependency collisions which lead to multiple versions of firebase-core.