title: Signed apk file crashes at the begining
body: <p><br/> <br/>
  The app work fine when i'm loading it from the Android Studio to my Nexus 5, but after I generated an apk file and install it on the device (after I uninstalled it) - it crashes when i'm trying to open the app.</p>
  
  <p>ERROR from LogCat:</p>
  
  <pre><code> --------- beginning of crash
  09-10 18:14:37.976  18853-18853/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
      Process: com.example.eladblau.myfamily, PID: 18853
      java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.eladblau.myfamily/com.example.eladblau.myfamily.MainActivity}: java.lang.IllegalArgumentException: Default constructor for class com.a.nj is not accessible.
              at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
              at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
              at android.app.ActivityThread.access$800(ActivityThread.java:151)
              at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
              at android.os.Handler.dispatchMessage(Handler.java:102)
              at android.os.Looper.loop(Looper.java:135)
              at android.app.ActivityThread.main(ActivityThread.java:5254)
              at java.lang.reflect.Method.invoke(Native Method)
              at java.lang.reflect.Method.invoke(Method.java:372)
              at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
              at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
       Caused by: java.lang.IllegalArgumentException: Default constructor for class com.a.nj is not accessible.
              at com.a.it.b(Unknown Source)
              at com.a.it.G(Unknown Source)
              at com.a.ek.a(Unknown Source)
              at com.example.eladblau.myfamily.m.b(Unknown Source)
              at com.example.eladblau.myfamily.m.&lt;init&gt;(Unknown Source)
              at com.example.eladblau.myfamily.m.a(Unknown Source)
              at com.example.eladblau.myfamily.MainActivity.onCreate(Unknown Source)
              at android.app.Activity.performCreate(Activity.java:5990)
              at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
              at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
              at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
              at android.app.ActivityThread.access$800(ActivityThread.java:151)
              at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
              at android.os.Handler.dispatchMessage(Handler.java:102)
              at android.os.Looper.loop(Looper.java:135)
              at android.app.ActivityThread.main(ActivityThread.java:5254)
              at java.lang.reflect.Method.invoke(Native Method)
              at java.lang.reflect.Method.invoke(Method.java:372)
              at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
              at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
  </code></pre>
  
  <p>Please help me! Thanks!</p>