title: NoSuchMethodError: No virtual method zzEq()Z in class Lcom/google/firebase/FirebaseApp;
body: <p>Below is the fatal error that I keep getting on my App. I am trying to run a chat messenger feature on my application using Firebase. It was running however it has since kept crashing the app entirely. I've made a few edits to the code in the hope of resolving the issues, but to no avail.</p>
  
  <p>I've been following this tutorial on youtbe <a href="https://www.youtube.com/watch?v=Xn0tQHpMDnM" rel="nofollow noreferrer">https://www.youtube.com/watch?v=Xn0tQHpMDnM</a> and it appears by reading the comments that no one else has a similiar error to me.</p>
  
  <p>According to the log, the errors are found on line 99 -  <code>displayChatMessage();</code> as well as on Line 109 - <code>adapter = new FirebaseListAdapter&lt;ChatMessage&gt;(this,ChatMessage.class,R.layout.chat_list_item,FirebaseDatabase.getInstance().getReference()) {</code></p>
  
  <p>I'm hoping this maybe just a simple code error which I have created, or is it possible it could be to do with my gradle build. Below is the error log I am getting.</p>
  
  <pre><code>FATAL EXCEPTION: main
                                                                                       Process: com.example.aids.a09application, PID: 30713
                                                                                       java.lang.NoSuchMethodError: No virtual method zzEq()Z in class Lcom/google/firebase/FirebaseApp; or its super classes (declaration of 'com.google.firebase.FirebaseApp' appears in /data/app/com.example.aids.a09application-2/split_lib_dependencies_apk.apk:classes33.dex)
                                                                                           at com.google.firebase.database.FirebaseDatabase.getInstance(Unknown Source)
                                                                                           at com.google.firebase.database.FirebaseDatabase.getInstance(Unknown Source)
                                                                                           at com.example.aids.a09application.MainChatActivity.displayChatMessage(MainChatActivity.java:109)
                                                                                           at com.example.aids.a09application.MainChatActivity.onCreate(MainChatActivity.java:99)
                                                                                           at android.app.Activity.performCreate(Activity.java:6912)
                                                                                           at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1126)
                                                                                           at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2877)
                                                                                           at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2985)
                                                                                           at android.app.ActivityThread.-wrap14(ActivityThread.java)
                                                                                           at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1635)
                                                                                           at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                           at android.os.Looper.loop(Looper.java:154)
                                                                                           at android.app.ActivityThread.main(ActivityThread.java:6692)
                                                                                           at java.lang.reflect.Method.invoke(Native Method)
                                                                                           at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1468)
                                                                                           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1358)
  </code></pre>
  
  <p>Below is the MainActivity Class for the chat messenger in my application:</p>
  
  <pre><code>package com.example.aids.a09application;
  
  import android.content.Intent;
  import android.os.Bundle;
  import android.support.annotation.NonNull;
  import android.support.annotation.Nullable;
  import android.support.design.widget.FloatingActionButton;
  import android.support.design.widget.Snackbar;
  import android.support.v7.app.AppCompatActivity;
  import android.view.Menu;
  import android.view.MenuItem;
  import android.view.View;
  import android.widget.EditText;
  import android.widget.ListView;
  import android.widget.RelativeLayout;
  import android.widget.TextView;
  import android.text.format.DateFormat;
  
  import com.firebase.ui.auth.AuthUI;
  import com.firebase.ui.database.FirebaseListAdapter;
  import com.google.android.gms.tasks.OnCompleteListener;
  import com.google.android.gms.tasks.Task;
  import com.google.firebase.auth.FirebaseAuth;
  import com.google.firebase.database.FirebaseDatabase;
  
  /**
   * Created by Aids on 29/08/2017.
   */
  
  public class MainChatActivity extends AppCompatActivity {
  
      private static int SIGN_IN_REQUEST_CODE = 1;
      private FirebaseListAdapter&lt;ChatMessage&gt; adapter;
      RelativeLayout chat_activity_main;
      FloatingActionButton fab;
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          if(item.getItemId() == (R.id.menu_signout))
          {
              AuthUI.getInstance().signOut( this ).addOnCompleteListener( new OnCompleteListener&lt;Void&gt;() {
                  @Override
                  public void onComplete(@NonNull Task&lt;Void&gt; task) {
                      Snackbar.make( chat_activity_main, "You have been signed out.", Snackbar.LENGTH_SHORT).show();
                      finish();
  
                  }
              } );
          }
          return true;
      }
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          getMenuInflater().inflate( R.menu.chat_main_menu, menu );
          return true;
      }
  
      @Override
      protected void onActivityResult(int requestCode, int resultCode, Intent data) {
          super.onActivityResult( requestCode, resultCode, data );
          if (requestCode == SIGN_IN_REQUEST_CODE)
          {
              if(resultCode == RESULT_OK)
              {
                  Snackbar.make( chat_activity_main, "Succesfully signed in. Welcome!", Snackbar.LENGTH_SHORT).show();
                  displayChatMessage();
              }
              else {
                  Snackbar.make( chat_activity_main, "We couldn't sign you in. Please try again!", Snackbar.LENGTH_SHORT).show();
                  finish();
              }
          }
      }
  
      @Override
      protected void onCreate(@Nullable Bundle savedInstanceState) {
          super.onCreate( savedInstanceState );
          setContentView( R.layout.chat_activity_main );
  
          chat_activity_main = (RelativeLayout) findViewById( R.id.chat_activity_main );
          fab = (FloatingActionButton) findViewById( R.id.fab );
          fab.setOnClickListener( new View.OnClickListener() {
              @Override
              public void onClick(View view) {
                  EditText input = (EditText)findViewById( R.id.input );
                  FirebaseDatabase.getInstance().getReference().push().setValue( new ChatMessage(input.getText().toString(),
                          FirebaseAuth.getInstance().getCurrentUser().getEmail()));
                  input.setText( "" );
  
              }
          } );
  
          if (FirebaseAuth.getInstance().getCurrentUser() == null) {
              startActivityForResult( AuthUI.getInstance().createSignInIntentBuilder().build(), SIGN_IN_REQUEST_CODE );
          } else {
              Snackbar.make( chat_activity_main, "Welcome" + FirebaseAuth.getInstance().getCurrentUser().getEmail(), Snackbar.LENGTH_SHORT ).show();
              //Load Content
              displayChatMessage();
          }
  
  
  
      }
  
      private void displayChatMessage() {
  
          ListView listofMessage = (ListView) findViewById( R.id.list_of_messages );
          adapter = new FirebaseListAdapter&lt;ChatMessage&gt;(this,ChatMessage.class,R.layout.chat_list_item,FirebaseDatabase.getInstance().getReference()) {
              @Override
              protected void populateView(View v, ChatMessage model, int position) {
                  //Get references to the views of chat_list_item.xml
  
                  TextView messageText, messageUser, messageTime;
                  messageText = (TextView) v.findViewById( R.id.message_text );
                  messageUser = (TextView) v.findViewById( R.id.message_user );
                  messageTime = (TextView) v.findViewById( R.id.message_time );
  
                  messageText.setText( model.getMessageText() );
                  messageUser.setText( model.getMessageUser() );
                  messageTime.setText( DateFormat.format( "dd-mm-yyyy (HH:MM:SS)",model.getMessageTime() ) );
              }
          };
  
          listofMessage.setAdapter( adapter );
  
      }
  
  }
  </code></pre>
  
  <p>Gradle Build Module:App</p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 26
      buildToolsVersion "26.0.1"
      defaultConfig {
          applicationId "com.example.aids.a09application"
          minSdkVersion 16
          targetSdkVersion 25
          versionCode 1
          versionName "1.0"
          testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
          aaptOptions.cruncherEnabled = false
          aaptOptions.useNewCruncher = false
  
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  android {
      useLibrary 'org.apache.http.legacy'
  }
  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.google.firebase:firebase-core:11.2.0'
      compile 'com.google.firebase:firebase-messaging:11.2.0'
      compile 'com.android.support:appcompat-v7:26.0.1'
      compile 'com.google.android.gms:play-services-maps:11.2.0'
      compile 'com.google.firebase:firebase-auth:11.2.0' // ADDED
      compile 'com.google.android.gms:play-services-auth:11.2.0' // ADDED
      compile 'com.android.support.constraint:constraint-layout:1.0.2'
      compile 'com.android.support:design:26.0.1'
      compile 'com.android.support:support-v4:26.0.1'
      compile 'com.android.support:recyclerview-v7:26.0.1'
      compile 'com.firebaseui:firebase-ui-auth:2.3.0'
      compile 'com.firebaseui:firebase-ui:2.3.0'
  }
  apply plugin: 'com.google.gms.google-services'
  </code></pre>