error: cannot find symbol import android.support.v4.app.NotificationManagerCompat;

[Imam-N]

My Config :

Project/build.gradle

buildscript { repositories { maven { url "https://maven.google.com" } jcenter() google() } dependencies {

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
    classpath 'com.android.tools.build:gradle:3.4.2'
    classpath 'com.google.gms:google-services:4.1.0'
}
configurations.all { resolutionStrategy { force 'com.android.support:support-v4:24.0.0' }}

}

app/build.gradle

compile "com.google.firebase:firebase-core:+"
compile "com.google.firebase:firebase-messaging:+"
compile "com.google.firebase:firebase-crash:+"
compile "com.google.firebase:firebase-config:+"
compile 'com.google.firebase:firebase-auth:16.+'

ComplieSdk Ver : 28

SDK - Support Repository

[krushitpatel]

same issue