I am seeing the following error in my Android crash reports:
android.os.BadParcelableException: ClassNotFoundException when unmarshalling: android.support.v4
I had the same error and here is what I did.
My issue came from using the ViewPager with a FragmentStatePagerAdapter. Inside one of the Fragments from the ViewPager had another ViewPager. Having that second view pager caused this rare bug. Even with or without an adapter on it.
The solution was to simply set setSaveEnabled(false); on the second ViewPager.