ClassNotFoundException when using library
<p>I'm making an app that uses external library:</p>

<ol>
<li>That library works with other project.</li>
<li>I checked that the jar included in class path.</li>
<li>And checked that all classes are in the place they should be.</li>
</ol>

<p>In that project I need to inherit from an activity in the library.
And I get the following error:</p>

<pre><code>03-11 11:48:07.578: E/asset(14711): MAS: getAppPckgAndVerCode package: com.nick.myplayer === version 1
03-11 11:48:07.588: W/dalvikvm(14711): Unable to resolve superclass of Lcom/mylib/lib/app/ActivityBase; (567)
03-11 11:48:07.588: W/dalvikvm(14711): Link of class 'Lcom/mylib/lib/app/ActivityBase;' failed
03-11 11:48:07.588: W/dalvikvm(14711): Unable to resolve superclass of Lcom/mylib/lib/app/ActivityLauncher; (607)
03-11 11:48:07.588: W/dalvikvm(14711): Link of class 'Lcom/mylib/lib/app/ActivityLauncher;' failed
03-11 11:48:07.588: W/dalvikvm(14711): Unable to resolve superclass of Lcom/nick/myplayer/MainActivity; (608)
03-11 11:48:07.588: W/dalvikvm(14711): Link of class 'Lcom/nick/myplayer/MainActivity;' failed
03-11 11:48:07.588: D/AndroidRuntime(14711): Shutting down VM
03-11 11:48:07.588: W/dalvikvm(14711): threadid=1: thread exiting with uncaught exception (group=0x40018560)
03-11 11:48:07.588: E/AndroidRuntime(14711): FATAL EXCEPTION: main
03-11 11:48:07.588: E/AndroidRuntime(14711): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.nick.myplayer/com.nick.myplayer.MainActivity}: java.lang.ClassNotFoundException: com.nick.myplayer.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.nick.myplayer-1.apk]
03-11 11:48:07.588: E/AndroidRuntime(14711):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1618)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1721)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at android.app.ActivityThread.access$1500(ActivityThread.java:124)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:968)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at android.os.Handler.dispatchMessage(Handler.java:99)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at android.os.Looper.loop(Looper.java:130)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at android.app.ActivityThread.main(ActivityThread.java:3844)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at java.lang.reflect.Method.invokeNative(Native Method)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at java.lang.reflect.Method.invoke(Method.java:507)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at dalvik.system.NativeStart.main(Native Method)
03-11 11:48:07.588: E/AndroidRuntime(14711): Caused by: java.lang.ClassNotFoundException: com.nick.myplayer.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.nick.myplayer-1.apk]
03-11 11:48:07.588: E/AndroidRuntime(14711):    at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
03-11 11:48:07.588: E/AndroidRuntime(14711):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1610)
</code></pre>

<p>Unfortunately I cannot put the source code.
Yet the app only inherites from that class.
Maybe some one know what I'm doing wrong. </p>
