title: Didn't find class "androidx.core.app.CoreComponentFactory"
body: <p>I don't know what to do about the following errors, I've searched the web but not found anything:</p>
  
  <pre><code>java.lang.ClassNotFoundException: Didn't find class "androidx.core.app.CoreComponentFactory" on path: DexPathList[[],nativeLibraryDirectories=[/data/app/com.example.padmw-CXElJ_vfrfm3y7py3CPsJw==/lib/x86, /system/lib]]
      at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:134)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
      at android.app.LoadedApk.createAppFactory(LoadedApk.java:226)
      at android.app.LoadedApk.updateApplicationInfo(LoadedApk.java:338)
      at android.app.ActivityThread.handleDispatchPackageBroadcast(ActivityThread.java:5388)
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1733)
      at android.os.Handler.dispatchMessage(Handler.java:106)
      at android.os.Looper.loop(Looper.java:193)
      at com.android.server.SystemServer.run(SystemServer.java:454)
      at com.android.server.SystemServer.main(SystemServer.java:294)
      at java.lang.reflect.Method.invoke(Native Method)
      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:838)
  </code></pre>
  
  <p>and :</p>
  
  <pre><code>2019-08-29 00:19:24.071 1853-1853/? E/LoadedApk: Unable to instantiate appComponentFactory
  java.lang.ClassNotFoundException: Didn't find class "androidx.core.app.CoreComponentFactory" on path: DexPathList[[],nativeLibraryDirectories=[/data/app/com.example.padmw-CXElJ_vfrfm3y7py3CPsJw==/lib/x86, /system/lib]]
      at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:134)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
      at android.app.LoadedApk.createAppFactory(LoadedApk.java:226)
      at android.app.LoadedApk.updateApplicationInfo(LoadedApk.java:338)
      at android.app.ActivityThread.handleDispatchPackageBroadcast(ActivityThread.java:5388)
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1733)
      at android.os.Handler.dispatchMessage(Handler.java:106)
      at android.os.Looper.loop(Looper.java:193)
      at com.android.server.SystemServer.run(SystemServer.java:454)
      at com.android.server.SystemServer.main(SystemServer.java:294)
      at java.lang.reflect.Method.invoke(Native Method)
      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:838)
  </code></pre>
  
  <p>my dependencies in gradle app :</p>
  
  <pre><code>dependencies {
  implementation fileTree(dir: 'libs', include: ['*.jar'])
  implementation 'androidx.appcompat:appcompat:1.0.2'
  implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
  implementation 'com.google.firebase:firebase-core:17.1.0'
  implementation 'com.google.firebase:firebase-database:19.0.0'
  implementation 'androidx.legacy:legacy-support-v4:1.0.0'
  implementation 'com.google.android.material:material:1.0.0'
  implementation 'androidx.navigation:navigation-fragment:2.0.0'
  implementation 'androidx.navigation:navigation-ui:2.0.0'
  implementation 'androidx.lifecycle:lifecycle-extensions:2.0.0'
  testImplementation 'junit:junit:4.12'
  androidTestImplementation 'androidx.test:runner:1.2.0'
  androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
  implementation 'androidx.recyclerview:recyclerview:1.0.0'
  implementation 'com.squareup.picasso:picasso:2.71828'
  implementation 'androidx.cardview:cardview:1.0.0'
  implementation 'com.firebaseui:firebase-ui-database:1.2.0'
  }
  apply plugin: 'com.google.gms.google-services'
  </code></pre>