Eu tenho uma biblioteca (jar) no caminho de compilação do meu projeto. O projeto acessa a MainActivity no jar, usando a seguinte intenção:

final Intent it = new Intent();
it.setClassName("com.example.lib", "com.example.lib.MainActivity");
startActivity(it);

Ele costumava funcionar por algum tempo, mas de repente começou a receber 'ActivityNotFoundException: nenhuma atividade encontrada para lidar com o Intent' que eu era capaz de resolver. Mas agora estou preso com um 'java.lang.SecurityException: Permission Denial: starting Intent'.

Eu tentei todas as sugestões feitas no stackoverflow (verifique se há duplicatas no arquivo de manifesto; adicione android: exportado = "true" ao lib manifest; Eclipse> Projeto> Limpar; adicionar / modificar as tags 'intent-filter' etc.). Eu até tentei reescrever o manifesto do projeto, mas não ir a lugar algum com ele.

Aqui está a saída do logcat:

11-07 06:20:52.176: E/AndroidRuntime(4626): FATAL EXCEPTION: main
11-07 06:20:52.176: E/AndroidRuntime(4626): java.lang.SecurityException: Permission     Denial: starting Intent { cmp=com.example.lib/.MainActivity } from ProcessRecord{40dd3778     4626:com.example.project/u0a10046} (pid=4626, uid=10046) not exported from uid 10047
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.os.Parcel.readException(Parcel.java:1425)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.os.Parcel.readException(Parcel.java:1379)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.app.ActivityManagerProxy.startActivity(ActivityManagerNative.java:1885)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.app.Instrumentation.execStartActivity(Instrumentation.java:1412)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.app.Activity.startActivityForResult(Activity.java:3370)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.app.Activity.startActivityForResult(Activity.java:3331)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:824)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.app.Activity.startActivity(Activity.java:3566)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.app.Activity.startActivity(Activity.java:3534)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at com.example.project.MainActivity.onOptionsItemSelected(MainActivity.java:93)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.app.Activity.onMenuItemSelected(Activity.java:2548)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.support.v4.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:366)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at com.android.internal.policy.impl.PhoneWindow.onMenuItemSelected(PhoneWindow.java:980)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at com.android.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:735)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:149)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:874)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at com.android.internal.view.menu.ActionMenuView.invokeItem(ActionMenuView.java:547)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at com.android.internal.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:115)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.view.View.performClick(View.java:4204)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.view.View$PerformClick.run(View.java:17355)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.os.Handler.handleCallback(Handler.java:725)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.os.Handler.dispatchMessage(Handler.java:92)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.os.Looper.loop(Looper.java:137)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at android.app.ActivityThread.main(ActivityThread.java:5041)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at java.lang.reflect.Method.invokeNative(Native Method)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at java.lang.reflect.Method.invoke(Method.java:511)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
11-07 06:20:52.176: E/AndroidRuntime(4626):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
11-07 06:20:52.176: E/AndroidRuntime(4626):     at dalvik.system.NativeStart.main(Native Method)

Manifesto XML do Projeto:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.project"
android:versionCode="4"
android:versionName="4.0" >

<!-- Permissions -->
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<supports-screens android:anyDensity="true" />

<!-- SDK Settings -->
<uses-sdk
    android:minSdkVersion="11"
    android:targetSdkVersion="18" />

<!-- APP Start -->
<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >

<!-- App Activity -->
    <activity
        android:name="com.example.project.MainActivity"
        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>

<!-- Library Activity -->
    <activity android:name="com.example.lib.MainActivity" android:label="LibMain">
         <intent-filter>
        <action android:name="android.intent.action.MAIN"></action>
     </intent-filter>
    </activity>

</application>
<!-- END - APP -->

</manifest>

O que eu estou negligenciando? Alguma sugestão?

EDITAR

Eu atualizei o manifest.xml com todas as outras atividades e de alguma forma, que resolveu o problema. A atividade intencional é iniciada sem erros.MAS, isso é apenas no AVD. No dispositivo real, ainda está jogando o mesmo erro. Eu desinstalei o aplicativo do dispositivo completamente e reinstalei, mas o mesmo erro.