Manifest merger failed with multiple errors, see logs on Android Studio

Question

The error says that "Error:Execution failed for task ':app:processDebugManifest'. > " I have tried many solutions on this website but still, the problem is not solved. Please help me

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="project.myapp">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"
        tools:replace="android:appComponentFactory">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

build.gradle(Module:app)

apply plugin: 'com.android.application'
apply plugin: 'com.jakewharton.butterknife'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "project.myapp"
        minSdkVersion 21
        targetSdkVersion 28
        multiDexEnabled true
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support:design:28.0.0'
//    implementation 'com.android.support:support-v4:27.1.1'
    implementation 'com.google.firebase:firebase-database:11.0.4'
    implementation 'com.google.firebase:firebase-auth:11.0.4'
    implementation 'com.google.firebase:firebase-storage:11.0.4'
    implementation 'com.firebaseui:firebase-ui-firestore:3.0.0'
    implementation 'de.hdodenhof:circleimageview:2.0.0'
    implementation 'com.github.bumptech.glide:glide:3.7.0'
    implementation 'com.jakewharton:butterknife:10.1.0'
    annotationProcessor 'com.jakewharton:butterknife-compiler:10.1.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

apply plugin: 'com.google.gms.google-services'

build.gradle(Project:myapp)

buildscript {

    repositories {
        google()
        jcenter()
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.0'


        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
        classpath 'com.google.gms:google-services:3.1.0'
        classpath 'com.jakewharton:butterknife-gradle-plugin:8.5.1'
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

On Merged Manifest says that

Merging Errors: Error: tools:replace specified at line:5 for attribute android:appComponentFactory, but no new value specified app main manifest (this file), line 4 Error: Validation failed, exiting app main manifest (this file)

Answer 1

For me, the solution was to just migrate to AndroidX.

On Android Studio, go to:

Refactor > Migrate to AndroidX

clean the project.