crash happen when showing the demo of 'Debug muti view types'

java.lang.IllegalArgumentException: ViewStub must have a valid layoutResource at android.view.ViewStub.inflate(ViewStub.java:284) at android.view.ViewStub.setVisibility(ViewStub.java:235) at com.marshalchen.ultimaterecyclerview.UltimateRecyclerView.updateHelperDisplays(UltimateRecyclerView.java:862) at com.marshalchen.ultimaterecyclerview.UltimateRecyclerView.access$400(UltimateRecyclerView.java:61) at com.marshalchen.ultimaterecyclerview.UltimateRecyclerView$3.onItemRangeInserted(UltimateRecyclerView.java:798) at android.support.v7.widget.RecyclerView$AdapterDataObservable.notifyItemRangeInserted(RecyclerView.java:11564) at android.support.v7.widget.RecyclerView$Adapter.notifyItemInserted(RecyclerView.java:6871) at com.marshalchen.ultimaterecyclerview.UltimateViewAdapter.insertInternal(UltimateViewAdapter.java:380) at com.marshalchen.ultimaterecyclerview.demo.multiitemdemo.MultiViewTypesRecyclerViewAdapter.insert(MultiViewTypesRecyclerViewAdapter.java:54) at com.marshalchen.ultimaterecyclerview.demo.multiitemdemo.MultiViewTypesActivity$1$1.run(MultiViewTypesActivity.java:72) at android.os.Handler.handleCallback(Handler.java:815) at android.os.Handler.dispatchMessage(Handler.java:104) at android.os.Looper.loop(Looper.java:207) at android.app.ActivityThread.main(ActivityThread.java:5975) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:679)