Android: Unable to instantiate activity / ClassNotFoundException

I recently published an app to the market and I'm now getting an error by some user, the app presumably crashes right when it starts. Unfortunately I can't contact him directly and the app works fine in the emulator as well as on my phone (and some friends' phones). EDIT: I guess that this happens to more than one user as I received comments in the market like "crashes on start" or "doesn't work". I only received this one stacktrace but there's no info about the configuration, device, Android version, etc. The app is a simple soundboard, so there's really no magic involved, but I can't get why it fails on some phones. Here's the stack trace I'm getting, I hope anybody can help me out: ``` java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.my.app/com.my.app.SoundMachine}: java.lang.ClassNotFoundException: com.my.app.SoundMachine in loader dalvik.system.PathClassLoader[/mnt/asec/com.my.app-1/pkg.apk] at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) at android.app.ActivityThread.access$2300(ActivityThread.java:125) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:123) at android.app.ActivityThread.main(ActivityThread.java:4627) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:521) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:876) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:634) at dalvik.system.NativeStart.main(Native Method) Caused by: java.lang.ClassNotFoundException: com.my.app.SoundMachine in loader dalvik.system.PathClassLoader[/mnt/asec/com.my.app-1/pkg.apk] at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243) at java.lang.ClassLoader.loadClass(ClassLoader.java:573) at java.lang.ClassLoader.loadClass(ClassLoader.java:532) at android.app.Instrumentation.newActivity(Instrumentation.java:1021) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577) ... 11 more ``` These are the first couple of lines from my activity: ``` public class SoundMachine extends Activity { private SoundManager mSoundManager; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); ``` EDIT: This is the (almost) complete onCreate: ``` @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mSoundManager = new SoundManager(); mSoundManager.initSounds(getBaseContext()); int counter = 0; for (Integer soundFile : soundFiles) { counter++; mSoundManager.addSound(counter, soundFile); } ImageButton SoundButton1 = (ImageButton) findViewById(R.id.sound1); SoundButton1.setOnClickListener(new OnClickListener() { public void onClick(View v) { mSoundManager.playSound(1); } }); SoundButton1.setOnLongClickListener(new OnLongClickListener() { public boolean onLongClick(View v) { saveSoundChoice(soundFiles[0], soundNames[0]); return true; } }); (...more of this...) Button StopButton = (Button) findViewById(R.id.stopbutton); StopButton.setOnClickListener(new OnClickListener() { public void onClick(View v) { mSoundManager.stopAll(); } }); } ``` And here's my manifest: ``` <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.my.app" android:installLocation="preferExternal" android:versionCode="9" android:versionName="1.2"> <application android:icon="@drawable/icon" android:label="@string/app_name"> <activity android:name=".SoundMachine" android:label="@string/app_name" android:screenOrientation="portrait"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> <uses-sdk android:minSdkVersion="3" android:targetSdkVersion="8" /> </manifest> ``` So all possible errors I already read about here and in some forums don't apply to my app. - The activity is present in the manifest. - The super-method is called in the overriden method. - The ContentView is set before accessing elements in the view. I know it's hard to pinpoint the source of an error without being able to reproduce it, but maybe somebody has a bright idea and can help me out. Some questions: - Do I need the "intent"-part in the manifest? Eclipse created it when I created the project. (Yes, according to Mayra) - Should the super-method be called where it is? (Yes, according to Mayra) EDIT: The main question that remains now is: How come the path in PathClassLoader is different from my package-name? The page John J Smith posted seems to deal with the same problem, but I don't understand the fix that was applied there. Thanks, Select0r