title: com.android.builder.dexing.DexArchiveMergerException: Unable to merge dex - Android Studio 3.0 stable
body: <p>I made:</p>
  
  <ul>
  <li>In "Settings"->"Android SDK"->"SDK Tools" Google Play services is checked and installed v.46</li>
  <li>Removed folder /.gradle</li>
  <li>"Clean Project"</li>
  <li>"Rebuild Project</li>
  </ul>
  
  <p>Error is:</p>
  
  <pre><code>Error:Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug'.
  &gt; java.lang.RuntimeException: java.lang.RuntimeException: com.android.builder.dexing.DexArchiveMergerException: Unable to merge dex
  </code></pre>
  
  <p><strong>Project build.gradle</strong></p>
  
  <pre><code>buildscript {
      repositories {
          jcenter()
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:3.0.0'
  
          classpath 'com.google.gms:google-services:3.1.0'
      }
  }
  
  allprojects {
      repositories {
          jcenter()
          google()
      }
  }
  
  task clean(type: Delete) {
      delete rootProject.buildDir
  }
  </code></pre>
  
  <p><strong>App build.gradle</strong></p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 26
      buildToolsVersion '26.0.2'
      defaultConfig {
          applicationId "com.asanquran.mnaum.quranasaanurdutarjuma"
          minSdkVersion 15
          targetSdkVersion 26
          versionCode 3
          versionName "1.3"
          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.+'
  
  
      compile 'com.android.support.constraint:constraint-layout:1.0.2'
      compile 'com.google.android.gms:play-services-ads:11.4.2'
      compile 'com.github.barteksc:android-pdf-viewer:2.3.0'
      compile 'org.apache.commons:commons-io:1.3.2'
      compile 'com.google.firebase:firebase-ads:11.4.2'
      compile 'com.google.firebase:firebase-messaging:11.4.2'
      compile 'com.google.firebase:firebase-storage:11.4.2'
      apply plugin: 'com.google.gms.google-services'
      testCompile 'junit:junit:4.12'
  }
  apply plugin: 'com.google.gms.google-services'
  </code></pre>