java.lang.NullPointerException

[cylonu87]

java.lang.NullPointerException: Attempt to invoke virtual method 'java.util.Iterator java.util.ArrayList.iterator()' on a null object reference
    at vs.refreshLibrary$6238c9b6(AbstractLibraryFragment.java:172)
    at vz.refreshLibrary$267a825a(LibraryMyAnimeListFragment.java:37)
    at vc$a.onPostExecute(RecyclerViewLibraryAdapter.java:359)
    at vc$a.onPostExecute(RecyclerViewLibraryAdapter.java:319)
    at android.os.AsyncTask.finish(AsyncTask.java:636)
    at android.os.AsyncTask.access$500(AsyncTask.java:177)
    at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:653)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:135)
    at android.app.ActivityThread.main(ActivityThread.java:5343)
    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:905)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)