Failing to launch activity due to ClassNotFoundException

Question

I am trying to launch a new activity using the code:

Intent i = new Intent(this, TempLobbyActivity.class);
startActivity(i);
finish();

When I launch this code I get the following exceptions when executing the Intent constructor.

FATAL EXCEPTION: main
Process: com.edr.iveflownthat, PID: 1457
java.lang.NoClassDefFoundError: Failed resolution of: Lcom/edr/iveflownthat/TempLobbyActivity;
    at com.edr.iveflownthat.pages.MainActivity.tryAutoLogin(MainActivity.java:46)
    at com.edr.iveflownthat.pages.MainActivity.onCreate(MainActivity.java:22)
    at android.app.Activity.performCreate(Activity.java:5933)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
    at android.app.ActivityThread.access$800(ActivityThread.java:144)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:135)
    at android.app.ActivityThread.main(ActivityThread.java:5221)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.ClassNotFoundException: Didn't find class     "com.edr.iveflownthat.TempLobbyActivity" on path: DexPathList[[zip file "/data/app/com.edr.iveflownthat-1/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
FATAL EXCEPTION: main
Process: com.edr.iveflownthat, PID: 1457
java.lang.NoClassDefFoundError: Failed resolution of: Lcom/edr/iveflownthat/TempLobbyActivity;
    at com.edr.iveflownthat.pages.MainActivity.tryAutoLogin(MainActivity.java:46)
    at com.edr.iveflownthat.pages.MainActivity.onCreate(MainActivity.java:22)
    at android.app.Activity.performCreate(Activity.java:5933)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
    at android.app.ActivityThread.access$800(ActivityThread.java:144)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:135)
    at android.app.ActivityThread.main(ActivityThread.java:5221)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.edr.iveflownthat.TempLobbyActivity" on path: DexPathList[[zip file "/data/app/com.edr.iveflownthat-1/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
    ... 15 more
Suppressed: java.lang.NoClassDefFoundError: com.edr.iveflownthat.TempLobbyActivity
    at dalvik.system.DexFile.defineClassNative(Native Method)
    at dalvik.system.DexFile.defineClass(DexFile.java:222)
    at dalvik.system.DexFile.loadClassBinaryName(DexFile.java:215)
    at dalvik.system.DexPathList.findClass(DexPathList.java:321)
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:54)
    ... 17 more
Suppressed: java.lang.ClassNotFoundException: com.edr.iveflownthat.TempLobbyActivity
    at java.lang.Class.classForName(Native Method)
    at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
    at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
    ... 16 more
Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available  at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
    ... 15 more
Suppressed: java.lang.NoClassDefFoundError: com.edr.iveflownthat.TempLobbyActivity
    at dalvik.system.DexFile.defineClassNative(Native Method)
    at dalvik.system.DexFile.defineClass(DexFile.java:222)
    at dalvik.system.DexFile.loadClassBinaryName(DexFile.java:215)
    at dalvik.system.DexPathList.findClass(DexPathList.java:321)
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:54)
    ... 17 more
Suppressed: java.lang.ClassNotFoundException: com.edr.iveflownthat.TempLobbyActivity
    at java.lang.Class.classForName(Native Method)
    at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
    at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
    ... 16 more
Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available

I have made sure that the class TempLobbyActivity does exist and is a proper activity. I get no other errors.

Here is the begining of TempLobbyActivity:

package com.edr.iveflownthat;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import com.edr.iveflownthat.pages.fragments.LobbyLeaderboardFragment;
import com.edr.iveflownthat.pages.fragments.LobbyMessagerFragment;
import com.edr.iveflownthat.pages.fragments.LobbyMyPlanesFragment;

public class TempLobbyActivity extends FragmentActivity {

And here is my manifest file:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.edr.iveflownthat"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="19" />

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.GET_ACCOUNTS" />
    <uses-permission android:name="android.permission.USE_CREDENTIALS" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/app_logo"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />

        <activity
            android:name=".pages.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".StartActivity"
            android:label="@string/title_activity_start" >
        </activity>
        <activity
            android:name=".pages.AccountLoginActivity"
        android:label="@string/title_activity_login" >
        </activity>
        <activity
            android:name=".pages.MyPlanesActivity"
            android:label="@string/title_activity_my_planes" >
        </activity>
        <activity
            android:name="com.edr.icom.edr.iveflownthat.activities.AccountNewActivity"
            android:label="@string/title_activity_new_account" >
        </activity>
        <activity
            android:name=".pages.SearchPlanesActivity"
            android:label="@string/title_activity_search"
            android:parentActivityName=".pages.LobbyActivity" >
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="com.edr.iveflownthat.pages.LobbyActivity" />
        </activity>
        <activity
            android:name=".pages.LeaderBoardActivity"
            android:label="@string/title_activity_leader_board" >
        </activity>
        <activity
            android:name=".pages.PlaneBioActivity"
            android:label="@string/title_activity_plane_info" >
        </activity>
        <activity
            android:name=".pages.AccountLoginFacebookActivity"
            android:label="@string/title_activity_account_login_facebook" >
        </activity>
        <activity
            android:name=".pages.AccountLoginGoogleActivity"
            android:label="@string/title_activity_account_login_google" >
        </activity>
        <activity
            android:name=".pages.AccountLoginTwitterActivity"
            android:label="@string/title_activity_account_login_twitter" >
        </activity>
        <activity
            android:name=".pages.SettingsActivity"
            android:label="@string/title_activity_settings" >
        </activity>
        <activity
            android:name=".pages.MainTabActivity"
            android:label="@string/title_activity_main_tab" >
        </activity>
        <activity
            android:name=".pages.LobbyActivity"
            android:label="@string/title_activity_lobby" >
        </activity>
        <activity
            android:name=".pages.MessageStreamActivity"
            android:label="@string/title_activity_message_stream"
            android:parentActivityName=".pages.LobbyActivity" >
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="com.edr.iveflownthat.pages.LobbyActivity" />
        </activity>
        <activity
            android:name=".pages.LeaderboardActivity"
            android:label="@string/title_activity_leaderboard"
            android:parentActivityName=".pages.LobbyActivity" >
        <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="com.edr.iveflownthat.pages.LobbyActivity" />
        </activity>

        <service
            android:name=".services.MainService"
            android:exported="false" />

        <activity
            android:name=".pages.NewMessageActivity"
            android:label="@string/title_activity_new_message" >
        </activity>
        <activity
            android:name=".pages.PlaneActivity"
            android:label="@string/title_activity_plane" >
        </activity>
        <!--
        <meta-data
            android:name="com.facebook.sdk.ApplicationId"
            android:value="@string/app_id" />

        <activity
            android:name="com.facebook.LoginActivity"
            android:label="@string/app_name" >
        </activity>
        -->
        <activity
            android:name=".TempLobbyActivity"
            android:label="@string/title_activity_temp_lobby" >
        </activity>
    </application>

</manifest>

Answer 1

I was getting the same error even though class was defined in AndroidManifest.xml.

Cause : Sometimes this happens as you add more than one version of appcompat library.

Solution : Remove any previous version of appcompat lib and add appcompat_v7.jar to your /lib folder.

Clean your project and build again. You might not get error again.