Android : Java Android Application Crash (Content Frame)

First sorry for my bad english, because I'm from germany. I develope a application for android devices.

I have a navigation in my app, like: - My Profile - Artist Page - Music Player - Blogs - Logout

Know if i click of Artist Page, Music player or Blogs, crash the app. If i click of my profile or logout is okey and no crash.

My Code:

String str = null;
Object localObject = null;
if (paramInt == 0)
{
  str = "Profile";
  localObject = new Profile();
  if (localObject == null) {}
}
for (;;)
{
  if (getSupportFragmentManager().getBackStackEntryCount() <= 0)
  {
    getSupportFragmentManager().beginTransaction().replace(R.id.content_frame, (Fragment)localObject).addToBackStack(str).commit();
    if (this.adapter != null) {
      this.adapter.setSelection(paramInt);
    }
    return; // ! If i remove this, crash the app. But if i not remove, i get unreached error.
    if (paramInt == 1)
    {
      str = "Jay's updates";
      localObject = new Updates();
      break;
    }
    if (paramInt == 2)
    {
      str = "Music Player";
      localObject = new Player();
      break;
    }
    localObject = null;
    str = null;
    if (paramInt != 3) {
      break;
    }
    str = "Blogs";
    localObject = new Blogs();
    break;
  }
  getSupportFragmentManager().popBackStackImmediate();
}

 }