Unable to merge dex

Question

I have Android Studio Beta. I created a new project with compile my old modules but when I tried launching the app it did not launch with the message:

Error:Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug'.

com.android.builder.dexing.DexArchiveMergerException: Unable to merge dex

But I don't know how to solve this error. I googled this for hours but with no success.

My project gradle:

    // Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
        google()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.0-beta6'
        classpath "io.realm:realm-gradle-plugin:3.7.1"
        classpath 'com.google.gms:google-services:3.1.0'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

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

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

My app gradle:

    apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    buildToolsVersion "26.0.1"
    defaultConfig {
        applicationId "parad0x.sk.onlyforyou"
        minSdkVersion 21
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        multiDexEnabled true
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
        debug {
        }
    }
    compileOptions {
        targetCompatibility 1.7
        sourceCompatibility 1.7
    }
    packagingOptions {
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/NOTICE'
    }
    lintOptions {
        checkReleaseBuilds false
    }
    productFlavors {
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    //noinspection GradleCompatible
    compile 'com.android.support:appcompat-v7:26.0.0-alpha1'
    compile project(path: ':loginregisterview')


}

And my module gradle:

    apply plugin: 'com.android.library'
apply plugin: 'realm-android'

android {
    compileSdkVersion 26
    buildToolsVersion "26.0.1"

    defaultConfig {
        minSdkVersion 19
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:26.0.2'
    compile 'com.android.support:support-v4:26.1.0'
    compile 'com.github.bumptech.glide:glide:4.0.0'
    testCompile 'junit:junit:4.12'
    compile project(path: ':parser')

}

My second module:

     apply plugin: 'com.android.library'
apply plugin: 'realm-android'

android {
    compileSdkVersion 26
    buildToolsVersion "26.0.1"
    defaultConfig {
        minSdkVersion 14
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

    }

    realm {
        syncEnabled = true
    }
    useLibrary 'org.apache.http.legacy'

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    productFlavors {
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile 'junit:junit:4.12'
    //  compile 'com.android.support:appcompat-v7:23.1.0'

    //   compile 'com.fasterxml.jackson.core:jackson-core:2.9.0'
 //   compile 'com.fasterxml.jackson.core:jackson-annotations:2.9.0'
 //   compile 'com.fasterxml.jackson.core:jackson-databind:2.9.0'
    compile 'com.google.code.gson:gson:2.6.2'
}

____________finding_________

When I did not import the second module (parser) the app did not crash on dex but when the module was not imported app did not work. :D :D

Answer 1

If this error appeared for you after including kotlin support, and none of the other solutions work, try changing the kotlin dependency of app module's build.gradle to:

implementation ("org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version") {
    exclude group: 'org.jetbrains', module: 'annotations'
}

This works for me on Android Studio 3.0 Beta 6. See this answer for further explanation.

Answer 2

With Android Studio 3.0 stable build Below steps worked for me:

1. Got to SdkManager-->Android Sdk --> Sdk Tools and Update Google play services to latest version to 46.
2. Clean project and rebuild project.

Answer 3

I also had the problem.

I was able to solve by changing compileSdkVersion and targetSdkVersion to latest version.

Answer 4

1. Enable

   defaultConfig { multiDexEnabled true }

2. If step 1 doesn't work then

   Go to project structure and find out the external library which is using a different version. Double click on it and delete its jar file. Close the project and open again android studio will rebuild the project. The problem should be gone.

Answer 5

I find out the reason of this problem for my project. I was added one dependency twice in build.gradle. One time by adding dependency and one time again by adding jar dependency:

compile 'org.achartengine:achartengine:1.2.0'
...
implementation files('../achartengine-1.2.0.jar')

after remove the first line problem solved.

Answer 6

Just to add to the above solutions:

Make sure that you don't have duplicate dependencies pointing to different versions of them, in multiple places (or even in the same file).