title: Gradle build error when trying to Generate Signed Apk
body: <p>About 34hours ago I generated a signed apk but now, I've been unable to generate a signed Apk and I have no idea on how to fix this. Please Help</p>
  
  <p>Here's my Output message</p>
  
  <blockquote>
    <p>Error:Note: there were 11 duplicate class definitions.
          (<a href="http://proguard.sourceforge.net/manual/troubleshooting.html#duplicateclass" rel="noreferrer">http://proguard.sourceforge.net/manual/troubleshooting.html#duplicateclass</a>)
    FAILURE: Build failed with an exception.</p>
    
    <ul>
    <li><p>What went wrong: Execution failed for task ':app:lintVitalRelease'.</p>
    
    <blockquote>
      <p>Could not resolve all files for configuration ':app:lintClassPath'.
      Could not resolve com.android.tools.lint:lint-gradle:26.1.0.
       Required by:
           project :app
      Could not resolve com.android.tools.lint:lint-gradle:26.1.0.
      Could not get resource '<a href="https://jcenter.bintray.com/com/android/tools/lint/lint-gradle/26.1.0/lint-gradle-26.1.0.pom" rel="noreferrer">https://jcenter.bintray.com/com/android/tools/lint/lint-gradle/26.1.0/lint-gradle-26.1.0.pom</a>'.
      Could not GET '<a href="https://jcenter.bintray.com/com/android/tools/lint/lint-gradle/26.1.0/lint-gradle-26.1.0.pom" rel="noreferrer">https://jcenter.bintray.com/com/android/tools/lint/lint-gradle/26.1.0/lint-gradle-26.1.0.pom</a>'.
      jcenter.bintray.com: nodename nor servname provided, or not known
      Could not resolve com.android.tools.lint:lint-gradle:26.1.0.
      Could not get resource '<a href="https://dl.google.com/dl/android/maven2/com/android/tools/lint/lint-gradle/26.1.0/lint-gradle-26.1.0.pom" rel="noreferrer">https://dl.google.com/dl/android/maven2/com/android/tools/lint/lint-gradle/26.1.0/lint-gradle-26.1.0.pom</a>'.
      Could not GET '<a href="https://dl.google.com/dl/android/maven2/com/android/tools/lint/lint-gradle/26.1.0/lint-gradle-26.1.0.pom" rel="noreferrer">https://dl.google.com/dl/android/maven2/com/android/tools/lint/lint-gradle/26.1.0/lint-gradle-26.1.0.pom</a>'.
      dl.google.com: nodename nor servname provided, or not known</p>
    </blockquote></li>
    <li><p>Try: Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.</p></li>
    <li><p>Get more help at <a href="https://help.gradle.org" rel="noreferrer">https://help.gradle.org</a></p></li>
    </ul>
    
    <p>BUILD FAILED in 10s</p>
  </blockquote>
  
  <p>Here's my build.gradle(app)</p>
  
  <pre><code>apply plugin: 'com.android.application'
  apply plugin: 'kotlin-android'
  apply plugin: 'io.fabric'
  
  android {
      compileSdkVersion 26
      buildToolsVersion '27.0.3'
      defaultConfig {
          applicationId "com.myapp……"
          minSdkVersion 17
          targetSdkVersion 26
          versionCode 5
          versionName "5.0"
      }
      buildTypes {
          release {
              minifyEnabled true
              shrinkResources true
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
      packagingOptions {
          exclude 'META-INF/NOTICE'
          exclude 'META-INF/LICENSE'
      }
  }
  
  dependencies {
      implementation fileTree(include: ['*.jar'], dir: 'libs')
      implementation "com.android.support:appcompat-v7:$support_version"
      implementation "com.android.support:design:$support_version"
      implementation "com.android.support:support-v4:$support_version"
      implementation "com.android.support:cardview-v7:$support_version"
      implementation "com.android.support:recyclerview-v7:$support_version"
      implementation "com.google.firebase:firebase-core:$firebase_version"
      implementation "com.google.firebase:firebase-messaging:$firebase_version"
      implementation "com.google.firebase:firebase-ads:$firebase_version"
      implementation 'com.crashlytics.sdk.android:crashlytics:2.9.1'
      implementation "com.google.firebase:firebase-perf:$firebase_version"
      implementation 'io.github.yavski:fab-speed-dial:1.0.6'
      implementation 'com.google.code.gson:gson:2.8.0'
      implementation 'com.codemybrainsout.rating:ratingdialog:1.0.8'
      implementation 'com.android.billingclient:billing:1.0'
      implementation 'com.android.support.constraint:constraint-layout:1.0.2'
      implementation 'org.jsoup:jsoup:1.10.3'
      testImplementation 'junit:junit:4.12'
      implementation "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
  }
  apply plugin: 'com.google.gms.google-services'
  
  apply plugin: 'kotlin-android-extensions'
  </code></pre>
  
  <p>Here's my build.gradle(project)</p>
  
  <pre><code>// Top-level build file where you can add configuration options common to all sub-projects/modules.
  
  buildscript {
      ext.kotlin_version = '1.2.10'
      ext.support_version = '26.1.0'
      ext.firebase_version = '12.0.1'
      repositories {
          jcenter()
          google()
          maven {
              url 'https://maven.fabric.io/public'
          }
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:3.1.0'
          classpath 'io.fabric.tools:gradle:1.25.1'
  
          // NOTE: Do not place your application dependencies here; they belong
          // in the individual module build.gradle files
          classpath 'com.google.gms:google-services:3.1.2'
          classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
      }
  }
  
  allprojects {
      repositories {
          jcenter()
          google()
      }
  }
  
  task clean(type: Delete) {
      delete rootProject.buildDir
  }
  </code></pre>