Error "Unable to instantiate activity ... Didn't find class on path: DexPathList"

Question

When I try to build the app on Eclipse, I get the following error:

05-20 15:04:51.202: E/AndroidRuntime(1543): FATAL EXCEPTION: main
05-20 15:04:51.202: E/AndroidRuntime(1543): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.devyanlab.testapp/com.devyanlab.testapp.activities.IntroActivity}: java.lang.ClassNotFoundException: Didn't find class "com.devyanlab.testapp.activities.IntroActivity" on path: DexPathList[[zip file "/data/app/com.devyanlab.testapp-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.devyanlab.testapp-1, /system/lib]]
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2137)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.os.Looper.loop(Looper.java:137)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.ActivityThread.main(ActivityThread.java:5103)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at java.lang.reflect.Method.invokeNative(Native Method)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at java.lang.reflect.Method.invoke(Method.java:525)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at dalvik.system.NativeStart.main(Native Method)
05-20 15:04:51.202: E/AndroidRuntime(1543): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.devyanlab.testapp.activities.IntroActivity" on path: DexPathList[[zip file "/data/app/com.devyanlab.testapp-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.devyanlab.testapp-1, /system/lib]]
05-20 15:04:51.202: E/AndroidRuntime(1543):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:53)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2128)
05-20 15:04:51.202: E/AndroidRuntime(1543):     ... 11 more

There are no errors in the application. I've tried (among other things):

• Cleaning the app
• Checking "Android Private Libraries" on Preferences > Java Build Path
• Checking activity paths on AndroidManifest.xml
• Restarting Eclipse multiple times
• Restarting the emulator (Genymotion)

Any thoughts?

Answer 1

Right click on your project and select properties. The "Properties for " panel will open. From the menu on the left go to Java Build Path -> Order and Export . From the list below check the libraries or external jar you added to your project. Finally clean your project and run.