title: Beta by Crashlytics - Package appears to be corrupted
body: <p>I recently developed an app for a client and now have to share it on Crashlytics for a Beta.
  I did this many times in the past but with this app, there's a problem.</p>
  
  <p>When I upload my app on Crashlytics Studio's plugin, there's no error. The email is correctly delivered to testers.</p>
  
  <p>But at the end of the installation, it says <strong>"The package appears to be corrupted"</strong>.</p>
  
  <p>This is the first time I see this and I don't know what to do.</p>
  
  <p>I try with all this type of APK:
  <em>- debug (unsigned)
  - release (unsigned)
  - release (signed)</em></p>
  
  <p>None of it works.</p>
  
  <p>Here's my build.gradle :</p>
  
  <pre><code>    buildscript {
      repositories {
          maven { url 'https://maven.fabric.io/public' }
      }
  
      dependencies {
          // These docs use an open ended version so that our plugin
          // can be updated quickly in response to Android tooling updates
  
          // We recommend changing it to the latest version from our changelog:
          // https://docs.fabric.io/android/changelog.html#fabric-gradle-plugin
          classpath 'io.fabric.tools:gradle:1.24.1'
      }
  }
  
  apply plugin: 'com.android.application'
  apply plugin: 'kotlin-android'
  apply plugin: 'kotlin-android-extensions'
  apply plugin: 'io.fabric'
  
  repositories {
      maven { url 'https://maven.fabric.io/public' }
      maven { url "https://jitpack.io" }
  }
  
  android {
  
      compileSdkVersion 26
      buildToolsVersion "26.0.1"
  
      defaultConfig {
          applicationId "com.xxxxxxx"
          minSdkVersion 15
          targetSdkVersion 26
          versionCode 3
          versionName "0.1.3"
          testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
          vectorDrawables.useSupportLibrary = true
          renderscriptSupportModeEnabled = true
      }
      buildTypes {
          release {
              minifyEnabled = true
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
              signingConfig signingConfigs.release
          }
      }
  }
  
  dependencies {
      implementation fileTree(dir: 'libs', include: ['*.jar'])
  
      /**
       * SUPPORT LIBS
       */
      implementation 'com.android.support:appcompat-v7:26.0.2'
      implementation 'com.android.support:recyclerview-v7:26.0.2'
      implementation 'com.android.support:design:26.0.2'
      implementation 'com.android.support.constraint:constraint-layout:1.0.2'
      implementation 'com.android.support:support-vector-drawable:26.0.2'
  
      /**
       * KOTLIN
       */
      implementation "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
  
      /**
       * UNIT TESTS
       */
      testImplementation 'junit:junit:4.12'
      androidTestImplementation('com.android.support.test.espresso:espresso-core:3.0.1', {
          exclude group: 'com.android.support', module: 'support-annotations'
      })
  
      /**
       * HTTP
       */
      implementation 'com.squareup.retrofit2:retrofit:2.3.0'
      implementation "com.squareup.retrofit2:converter-gson:2.3.0"
      implementation "com.squareup.retrofit2:adapter-rxjava:2.3.0"
      implementation 'com.squareup.okhttp3:logging-interceptor:3.8.0'
  
      /**
       * INJECTION LIB
       */
      implementation 'com.jakewharton:butterknife:8.8.1'
      annotationProcessor 'com.jakewharton:butterknife-compiler:8.8.1'
  
      /**
       * COMPONENT LIBS
       */
      implementation('com.mikepenz:fastadapter:2.6.3@aar') {
          transitive = true
      }
      implementation 'com.mikepenz:fastadapter-commons:2.6.3@aar'
      implementation 'com.mikepenz:fastadapter-extensions:2.6.3@aar'
  
      /**
       * IMAGE LOADING/CACHING/EDITING LIBS
       */
      implementation 'com.github.bumptech.glide:glide:4.1.1'
      annotationProcessor 'com.github.bumptech.glide:compiler:4.1.1'
      implementation 'com.makeramen:roundedimageview:2.3.0'
  
      /**
       * PLAYERS VIDEO/MUSIC
       */
      implementation 'com.google.android.exoplayer:exoplayer:r2.0.0'
      implementation 'com.dailymotion.dailymotion-sdk-android:sdk:0.1.12'
  
      /**
       * EVENTBUS
       */
      implementation 'org.greenrobot:eventbus:3.0.0'
  
      /**
       * Overscroll
       */
      implementation 'com.scwang.smartrefresh:SmartRefreshLayout:1.0.3'
      implementation 'com.scwang.smartrefresh:SmartRefreshHeader:1.0.3'
  
      /**
       * FABRIC/CRASHLYTICS
       */
      implementation('com.crashlytics.sdk.android:crashlytics:2.6.8@aar') {
          transitive = true
      }
  }
  </code></pre>
  
  <p>How can I solve it?</p>