Didn't find class "com.example.app.MainActivity"

Question

I got this error in flutter debugging the android build. I didn't find out the exact solution for this. Please help to solve this.

Launching lib/main.dart on SM M105F in debug mode... Running Gradle task 'assembleDebug'... Purging debug resources in release build ✓ Built build/app/outputs/flutter-apk/app-debug.apk. Installing build/app/outputs/flutter-apk/app.apk... E/AndroidRuntime(22297): FATAL EXCEPTION: main E/AndroidRuntime(22297): Process: com.example.app, PID: 22297 E/AndroidRuntime(22297): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.app/com.example.app.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.example.app.MainActivity" on path: DexPathList[[zip file "/data/app/com.example.app-8SDv03NkHqZSCPu3ZprpAQ==/base.apk"],nativeLibraryDirectories=[/data/app/com.example.app-8SDv03NkHqZSCPu3ZprpAQ==/lib/arm, /data/app/com.example.app-8SDv03NkHqZSCPu3ZprpAQ==/base.apk!/lib/armeabi-v7a, /system/lib, /vendor/lib]] E/AndroidRuntime(22297): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3449) E/AndroidRuntime(22297): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3703) E/AndroidRuntime(22297): at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) E/AndroidRuntime(22297): at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) E/AndroidRuntime(22297): at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) E/AndroidRuntime(22297): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2216) E/AndroidRuntime(22297): at android.os.Handler.dispatchMessage(Handler.java:107) E/AndroidRuntime(22297): at android.os.Looper.loop(Looper.java:237) E/AndroidRuntime(22297): at android.app.ActivityThread.main(ActivityThread.java:7948) E/AndroidRuntime(22297): at java.lang.reflect.Method.invoke(Native Method) E/AndroidRuntime(22297): at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) E/AndroidRuntime(22297): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1075) E/AndroidRuntime(22297): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.app.MainActivity" on path: DexPathList[[zip file "/data/app/com.example.app-8SDv03NkHqZSCPu3ZprpAQ==/base.apk"],nativeLibraryDirectories=[/data/app/com.example.app-8SDv03NkHqZSCPu3ZprpAQ==/lib/arm, /data/app/com.example.app-8SDv03NkHqZSCPu3ZprpAQ==/base.apk!/lib/armeabi-v7a, /system/lib, /vendor/lib]] E/AndroidRuntime(22297): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:196) E/AndroidRuntime(22297): at java.lang.ClassLoader.loadClass(ClassLoader.java:379) E/AndroidRuntime(22297): at java.lang.ClassLoader.loadClass(ClassLoader.java:312) E/AndroidRuntime(22297): at android.app.AppComponentFactory.instantiateActivity(AppComponentFactory.java:95) E/AndroidRuntime(22297): at androidx.core.app.CoreComponentFactory.instantiateActivity(CoreComponentFactory.java:45) E/AndroidRuntime(22297): at android.app.Instrumentation.newActivity(Instrumentation.java:1251) E/AndroidRuntime(22297): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3437) E/AndroidRuntime(22297): ... 11 more

Answer 1

Open your AndroidManifest.xml and check if you have com.example.app.MainActivity :

<activity
    android:name="com.example.app.MainActivity"
    android:label="@string/app_name" >
</activity>