The library com.google.android.gms:play-services-basement is being requested by various other libraries at [[15.0.1,15.0.1]], but resolves to 16.1.0. Disable the plugin and check your dependencies tree using ./gradlew :app:dependencies.
This error always pops whenever i add the below plugin to my project which is connected to firebase. apply plugin: 'com.google.gms.google-services'