Android ClassNotFoundException: Didn't find class on path

Question

I can't find the solution of this error. Can you please give the permanent solution? I have no idea how to solve it.

01-04 11:06:42.302: E/AndroidRuntime(1906): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{e.gochat/e.gochat.gochat.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "e.gochat.gochat.MainActivity" on path: DexPathList[[zip file "/data/app/e.gochat-1.apk"],nativeLibraryDirectories=[/data/app-lib/e.gochat-1, /vendor/lib, /system/lib]]
01-04 11:06:42.302: E/AndroidRuntime(1906):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2102)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at android.app.ActivityThread.access$700(ActivityThread.java:135)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at android.os.Handler.dispatchMessage(Handler.java:102)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at android.os.Looper.loop(Looper.java:137)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at android.app.ActivityThread.main(ActivityThread.java:4998)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at java.lang.reflect.Method.invokeNative(Native Method)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at java.lang.reflect.Method.invoke(Method.java:515)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at dalvik.system.NativeStart.main(Native Method)
01-04 11:06:42.302: E/AndroidRuntime(1906): Caused by: java.lang.ClassNotFoundException: Didn't find class "e.gochat.gochat.MainActivity" on path: DexPathList[[zip file "/data/app/e.gochat-1.apk"],nativeLibraryDirectories=[/data/app-lib/e.gochat-1, /vendor/lib, /system/lib]]
01-04 11:06:42.302: E/AndroidRuntime(1906):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
01-04 11:06:42.302: E/AndroidRuntime(1906):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2093)
01-04 11:06:42.302: E/AndroidRuntime(1906):     ... 11 more
01-04 11:07:06.772: I/Process(1906): Sending signal. PID: 1906 SIG: 9
 

This is my app Manifest XML

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="e.gochat"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="9"
    android:targetSdkVersion="18" />
<permission
    android:name="e.gochat.permission.C2D_MESSAGE"
    android:protectionLevel="signature" />

<uses-permission android:name="e.gochat.permission.C2D_MESSAGE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<uses-permission android:name="android.permission.READ_CONTACTS" />
 
<application
    android:name="e.gochat.Common"
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
   
    
    <activity
        android:name="e.gochat.MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
     <activity android:name="e.gochat.ChatActivity" 
        />
    <activity
        android:name="e.gochat.SettingsActivity"
        android:label="@string/title_activity_settings" />
    <receiver
        android:name="e.gochat.client.GcmBroadcastReceiver"
        android:permission="com.google.android.c2dm.permission.SEND" >
        <intent-filter>
            <action android:name="com.google.android.c2dm.intent.RECEIVE" />

            <category android:name="e.gochat" />
        </intent-filter>
    </receiver>
    <provider
        android:name="e.gochat.DataProvider"
        android:authorities="e.gochat.provider" 
        android:exported="false">
    </provider>
   
    
</application>

I'm not sure what's wrong here. I've added the .jar file in the java build path. And yet I'm getting this classnotfound exception. The app loads when I import the android.app.Application

Outrush

Somewhere you are using e.gochat.gochat.MainActivity but you have declared the name e.gochat.MainActivity in AndroidManifest.xml – Jorgenson

I had the same issue and fixed it with that solution : https://mcmap.net/q/330946/-classnotfoundexception-on-androidannotations-generated-classes-since-update-to-adt-22 – Coralloid

Answer 1

I don't know for sure what is your package name, but if it is e.gochat do this.

Add package="e.gochat" to manifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="e.gochat"
    .....
    .....
         >

On each activity declaration for android:name put a dot before activity name:

<activity
    android:name=".MainActivity">
............
</activity>

<activity 
    android:name=".ChatActivity">

EDIT

After your edited I can see e.gochat is your package name.
Now you only need to remove e.gochat from each activity/provider/receiver name as I said in second part of my answer.
Android will add that for you.

Spies

Why does dot have to be used before Activity name? Why can't provide the full package path for Activity name?? – Chary

@Chary You can provide the full path if package="e.gochat" is not used(is removed). – Spies

Dears, i have faced same problem, and fix the package name as ramaral mention, but not fixed until I clean the project, then make project then build and run, and now it's working fine. – Rebozo

Answer 2

I have solved this problem by disabling the instant run option of android studio. To disable Instant Run Goto File -> Settings -> Build,Execution, Deployment -> Instant Run -> Uncheck the checkbox for instant run

Alkyne

I wanteed to rename a project. After clossing Android Studio, renaming whole project in file explorer, and importing it with desired name again to Android Studio, it started the issue asked above in the original question . Your answer only helped. – Autolycus

@Autolycus Same problem here - I think a lot of people will google solution and get to this page. Hopefully they'll see this answer... – Preglacial

you saved my life Thank you very much – Psephology

I think android studio has serious bug , the project was working fine in api 17 but when i tried to debug on 24 it was through this exception, even though if i transfer the app through other means (via bluetooth ) the app was working fine in 24 , any way thanks for saving my life – Epicurean

this worked for me! but i do not know, what is the reason?! – Veritable

Answer 3

Using Android Studio

After upgrading to Android Stuido 0.8.2, I had this problem. I tried a lot of things, including

• Clean project
• Clean project (gradle clean)
• Invalidate Caches and Restart
• De-qualify the Activity Name in AndroidManifest.xml (.MyActivity)

Nothing worked until I re-imported the entire project.

File -> Close Project -> Import Project... -> Choose the same project -> OK

This fixed it for me

Chenoweth

Answer 4

Uninstalling the app in the device and running the project again fixed it for me.

Guss

Uninstalling and then running the app worked for me. Thanks. I run into this problem after not updating Android Studio for a while (many weeks). As of the writing of this post, I am now running this version -> Android Studio 2.2 Build #AI-145.3276617, built on September 15, 2016 JRE: 1.8.0_76-release-b03 x86_64 JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o – Sundew

Answer 5

The reason why this was affecting me was due to an incorrect path name in a layout file

<android.support.v4.app.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"> 

</android.support.v4.app.view.ViewPager>

The correct absolute path of ViewPager is

android.support.v4.view.ViewPager

After correcting the path it worked. I did not have to prefix the activity name with a '.'.

Grackle

You save my day , that happen in my project and specially in package com.neopixl.pixlui.MainActivity Thanks a lot – Marienthal

Answer 6

For me, this was occurring on devices running < Android 5.0 because I didn't have multidex support enabled (this is, over 65k total methods incl. libs). Multidex is automatic and native on Android 5.0+ (specifically, devices using ART).

Outlaw

Answer 7

The problem was solved by removing MultiDexSupport from build.gradle file :

defaultConfig {
    multiDexEnabled true    // This line was causing above problem
}

Removing the MultiDexSupport solved the problem

Tyndall

Well, adding this line fixed the error for me, Thanks :) any explanation for this? – Climax

Android platform imposes 64K limit for size of referenced methods, to avoid this we can enable multi-dex support. So, I enabled multiDex support and my unfound classes were properly compiled into classes.dex and exception was resolved – Tyndall

Answer 8

This issue has multiple answers based on the different scenario. I was getting the same error when using a library(.aar) in my Android Studio project.

The root cause in my case was that I missed to add a third party lib dependency in app's build.gradle file which was being used by the .aar file.

e.g:- The library(.aar) was using 'com.squareup.okhttp3:okhttp:3.4.1'. So I had to add

compile 'com.squareup.okhttp3:okhttp:3.4.1'

in the app's build.gradle. Hope it helps someone.

Democracy

Answer 9

For me the issue occurred as I wasn't including the kotlin-android and kotlin-android-extensions plugins in my :app modules build.gradle.

E.g.

plugins {
    id 'com.android.application'
    id 'kotlin-android'
    id 'kotlin-android-extensions'
}

Or if you're using the Kotlin DSL

plugins {
    id("com.android.application")
    kotlin("android")
    kotlin("android.extensions")
}

Insignificance

This was my issue. I used Android Studio to convert my main activity to Kotlin and never got any warnings or prompts to configure it as described here: developer.android.com/kotlin/add-kotlin Using Help -> Find Action I got the Configure Kotlin dialog and that edited gradle automatically for me. – Dactylography

Answer 10

ANDROID STUDIO In addittion to Kishor's answer:

The error occured on my small project when I enabled multiDexEnabled = true in the gradle defaultconfig. Using the generated .apk file crashes on start of the app with the known error message.

For me it was solved when I built the .apk file via gradle (right side of android studio) -> "yourapp" -> Tasks- > install -> installDebug

Hope this helps someone with this strange error

Seaquake

I have the same problem – Shoreless

Answer 11

I implemented a listener that was not available in the android version I was running yet and this led to the same error.

Example MainActivity:

// RecyclerView.OnScrollChangeListener is only available on API >= 23
public class MainActivity implements RecyclerView.OnScrollChangeListener
{

}

Running this activity on a device with API < 23 will result in this error as well...

Liquorice

Answer 12

If you tried other solitions and none of them work. Sometimes this error happen because some library use Java 8 features. To solve the problem, configure Android Gradle Plugin to support Java 8 by adding the following code to your build.gradle file

compileOptions {
   sourceCompatibility JavaVersion.VERSION_1_8
   targetCompatibility JavaVersion.VERSION_1_8
}

Lordinwaiting

Answer 13

dependencies {
    implementation 'androidx.appcompat:appcompat:+'
    implementation 'androidx.constraintlayout:constraintlayout:+'
}

Remove this line from Gradle

Medeiros