Build Failed - Task :app:checkDebugDuplicateClasses FAILED

Question

I was using Unity ads in my Android Studio Java application, then I wanted to migrate Appodeal, Appodeal supports Androidx, I tried to make my application androidx, I edited many files, but I can't get past this error. Can you help me. Where am I doing wrong?

Project Build.Grandle

 // Top-level build file where you can add configuration options common to all sub-projects/modules. buildscript { repositories { google() jcenter() } dependencies { classpath 'com.android.tools.build:gradle:4.1.2' // NOTE: Do not place your application dependencies here; they belong // in the individual module build.gradle files classpath 'com.google.gms:google-services:4.3.3' } } allprojects { repositories { google() jcenter() maven { url 'https://maven.google.com'} maven { url "https://artifactory.appodeal.com/appodeal" } } } task clean(type: Delete) { delete rootProject.buildDir }

Module Build.Grandle

 apply plugin: 'com.android.application' android { compileSdkVersion 31 defaultConfig { applicationId "com.app.app" minSdkVersion 21 targetSdkVersion 31 versionCode 15 versionName '15' vectorDrawables.useSupportLibrary = true multiDexEnabled true } buildTypes { release { minifyEnabled true proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' } } compileOptions { sourceCompatibility JavaVersion.VERSION_1_8 targetCompatibility JavaVersion.VERSION_1_8 } ndkVersion '23.0.7123448 rc1' buildToolsVersion '31.0.0 rc1' } dependencies { implementation fileTree(include: ['*.jar'], dir: 'libs') implementation 'androidx.appcompat:appcompat:1.4.0' implementation 'androidx.recyclerview:recyclerview:1.1.0' //noinspection GradleCompatible implementation 'com.google.android.material:material:1.0.0' implementation 'com.google.firebase:firebase-database:20.0.3' implementation 'com.google.android.gms:play-services-base:18.0.1' implementation 'com.google.android.gms:play-services-auth:20.0.1' implementation 'androidx.cardview:cardview:1.0.0' implementation 'de.hdodenhof:circleimageview:2.2.0' implementation 'com.squareup.picasso:picasso:2.3.1' implementation 'androidx.browser:browser:1.0.0' implementation 'androidx.annotation:annotation:1.0.0' implementation 'com.github.guilhe:circular-progress-view:1.2.1' implementation 'com.android.installreferrer:installreferrer:1.0' // implementation 'com.google.firebase:firebase-ads:17.1.1' implementation 'com.google.firebase:firebase-config:21.0.1' implementation 'com.appodeal.ads:sdk:2.11.0.+' implementation 'com.google.firebase:firebase-core:17.2.1' implementation 'com.google.firebase:firebase-messaging:20.0.0' implementation 'com.google.firebase:firebase-auth:19.1.0' // implementation 'com.android.support:multidex:2.0.3' } apply plugin: 'com.google.gms.google-services'

Build Failed

 > Task:app:checkDebugDuplicateClasses FAILED Execution failed for task ':app:checkDebugDuplicateClasses'. > A failure occurred while executing com.android.build.gradle.internal.tasks.CheckDuplicatesRunnable > Duplicate class com.google.android.gms.internal.measurement.zzbj found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-sdk-api-18.0.3-runtime (com.google.android.gms:play-services-measurement-sdk-api:18.0.3) Duplicate class com.google.android.gms.internal.measurement.zzbk found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-sdk-api-18.0.3-runtime (com.google.android.gms:play-services-measurement-sdk-api:18.0.3) Duplicate class com.google.android.gms.internal.measurement.zzbl found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-sdk-api-18.0.3-runtime (com.google.android.gms:play-services-measurement-sdk-api:18.0.3) Duplicate class com.google.android.gms.internal.measurement.zzbm found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-sdk-api-18.0.3-runtime (com.google.android.gms:play-services-measurement-sdk-api:18.0.3) Duplicate class com.google.android.gms.internal.measurement.zzbn found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-sdk-api-18.0.3-runtime (com.google.android.gms:play-services-measurement-sdk-api:18.0.3) Duplicate class com.google.android.gms.internal.measurement.zzbo found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-sdk-api-18.0.3-runtime (com.google.android.gms:play-services-measurement-sdk-api:18.0.3) Duplicate class com.google.android.gms.internal.measurement.zzbp found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-sdk-api-18.0.3-runtime (com.google.android.gms:play-services-measurement-sdk-api:18.0.3) Duplicate class com.google.android.gms.internal.measurement.zzbq found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-sdk-api-18.0.3-runtime (com.google.android.gms:play-services-measurement-sdk-api:18.0.3) Duplicate class com.google.android.gms.internal.measurement.zzbr found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-sdk-api-18.0.3-runtime (com.google.android.gms:play-services-measurement-sdk-api:18.0.3) Duplicate class com.google.android.gms.internal.measurement.zzbs found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-sdk-api-18.0.3-runtime (com.google.android.gms:play-services-measurement-sdk-api:18.0.3) Duplicate class com.google.android.gms.internal.measurement.zzi found in modules jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) and jetified-play-services-measurement-sdk-api-18.0.3-runtime (com.google.android.gms:play-services-measurement-sdk-api:18.0.3) Duplicate class com.google.android.gms.internal.measurement.zzir found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzit found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zziu found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zziv found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zziw found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzix found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zziy found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zziz found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzj found in modules jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) and jetified-play-services-measurement-sdk-api-18.0.3-runtime (com.google.android.gms:play-services-measurement-sdk-api:18.0.3) Duplicate class com.google.android.gms.internal.measurement.zzja found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjb found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjc found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjd found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzje found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjf found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjg found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjh found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzji found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjj found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjk found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjl found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjm found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjn found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjo found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjp found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjq found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjr found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjs found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjt found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzju found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjv found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjw found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjx found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjy found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzjz found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzka found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzkb found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzkc found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzkd found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzke found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzkf found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzkg found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzkh found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzki found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzkj found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzkk found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzkl found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.internal.measurement.zzkm found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.measurement.internal.zzfh found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.measurement.internal.zzgl found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) Duplicate class com.google.android.gms.measurement.internal.zzgm found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) Duplicate class com.google.android.gms.measurement.internal.zzgn found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) Duplicate class com.google.android.gms.measurement.internal.zzgo found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) Duplicate class com.google.android.gms.measurement.internal.zzgp found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) Duplicate class com.google.android.gms.measurement.internal.zzgq found in modules jetified-play-services-measurement-17.2.1-runtime (com.google.android.gms:play-services-measurement:17.2.1) and jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) Duplicate class com.google.android.gms.measurement.internal.zzhs found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1) Duplicate class com.google.android.gms.measurement.internal.zzhx found in modules jetified-play-services-measurement-base-18.0.3-runtime (com.google.android.gms:play-services-measurement-base:18.0.3) and jetified-play-services-measurement-impl-17.2.1-runtime (com.google.android.gms:play-services-measurement-impl:17.2.1)

Answer 1

It sounds like something is wrong with your Gradle,

try the steps in this similar answer:

Go to gradle.properties(project properties)

Add android.enableJetifier=true

And also most of time android.useAndroidX=true is present.Check your gradle.properties(Project Properties) and if it does not exist then add android.useAndroidX=true

Quote from that thread: If you want to use androidx-namespaced libraries in a new project, you need to set the compile SDK to Android 9.0 (API level 28) or higher and set both of the mentioned Android Gradle plugin flags to true.

android.useAndroidX: When this flag is set to true, the Android plugin uses the appropriate AndroidX library instead of a Support Library. The flag is false by default if it is not specified.

android.enableJetifier: When this flag is set to true, the Android plugin automatically migrates existing third-party libraries to use AndroidX dependencies by rewriting their binaries. The flag is false by default if it is not specified.

Execution failed for task ':app:checkDebugDuplicateClasses'. Ionic4 Android