title: Error only in exported APK: Unable to instantiate activity ComponentInfo
body: <p>When I run my app directly from Android Developer Tools (ADT), it works fine. However, when I export it to an APK file and install it, I get the following error:</p>
  
  <blockquote>
    <p>java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{my.app/my.app.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "my.app.MainActivity" on path: DexPathList[[zip file "/data/app/my.app-2.apk"],nativeLibraryDirectories=[/data/app-lib/my.app-2, /vendor/lib, /system/lib]]
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2187)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2311)
    at android.app.ActivityThread.access$600(ActivityThread.java:149)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1293)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:137)
    at android.app.ActivityThread.main(ActivityThread.java:5214)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:525)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:739)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555)
    at dalvik.system.NativeStart.main(Native Method)
    Caused by: java.lang.ClassNotFoundException: Didn't find class "my.app.MainActivity" on path: DexPathList[[zip file "/data/app/my.app-2.apk"],nativeLibraryDirectories=[/data/app-lib/my.app-2, /vendor/lib, /system/lib]]
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:53)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
    at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2178)
    ... 11 more</p>
  </blockquote>