title: Multiple dex files define Lorg/apache/cordova/BuildHelper
body: <p>I'm in trouble since yesterday. In my internship I faced the following build error, but I couldn't understand why :</p>
  
  <pre><code>$ cordova build android
  
  [...]
  
  FAILURE: Build failed with an exception.
  
  * What went wrong:
  Execution failed for task ':transformClassesWithDexForDebug'.
  &gt; com.android.build.api.transform.TransformException: com.android.ide.common.process.ProcessException: java.util.concurrent.ExecutionException: com.android.dex.DexException: Multiple dex files define Lorg/apache/cordova/BuildHelper;
  
  * Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
  
  BUILD FAILED
  
  Total time: 3.379 secs
  Error: /home/thor/Projects/App_CDP/platforms/android/gradlew: Command failed with exit code 1 Error output:
  Note: Some input files use or override a deprecated API.
  Note: Recompile with -Xlint:deprecation for details.
  Note: Some input files use unchecked or unsafe operations.
  Note: Recompile with -Xlint:unchecked for details.
  
  FAILURE: Build failed with an exception.
  
  * What went wrong:
  Execution failed for task ':transformClassesWithDexForDebug'.
  &gt; com.android.build.api.transform.TransformException: com.android.ide.common.process.ProcessException: java.util.concurrent.ExecutionException: com.android.dex.DexException: Multiple dex files define Lorg/apache/cordova/BuildHelper;
  
  * Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
  </code></pre>
  
  <p>Here is the output of <code>cordova plugins list</code>, I don't have the support-v4/v13 conflict as you can see :</p>
  
  <pre><code>$ cordova plugin list
  com.googlemaps.ios 2.2.0-fixed "Google Maps SDK for iOS"
  com.moust.cordova.videoplayer 1.0.1 "Video Player"
  cordova-plugin-camera 2.4.1 "Camera"
  cordova-plugin-compat 1.1.0 "Compat"
  cordova-plugin-console 1.0.5 "Console"
  cordova-plugin-device 1.1.4 "Device"
  cordova-plugin-facebook4 1.9.1 "Facebook Connect"
  cordova-plugin-file 4.0.0 "File"
  cordova-plugin-file-transfer 1.6.3 "File Transfer"
  cordova-plugin-geolocation 2.4.3 "Geolocation"
  cordova-plugin-googlemaps 1.4.0 "phonegap-googlemaps-plugin"
  cordova-plugin-inappbrowser 1.7.1 "InAppBrowser"
  cordova-plugin-splashscreen 4.0.3 "Splashscreen"
  cordova-plugin-statusbar 2.2.2 "StatusBar"
  cordova-plugin-whitelist 1.3.1 "Whitelist"
  ionic-plugin-keyboard 2.2.1 "Keyboard"
  {}
  </code></pre>
  
  <p>Here are also some more informations:</p>
  
  <pre><code>$ cordova -v
  7.0.1
  
  $ ionic -v
  2.1.4
  </code></pre>