1. getItemSize==0 일 때 @Override public int getItemCount() { Log.e(TAG, "itemList.size(): "+itemList.size()); return itemList.size(); } 2. LayoutManger를 셋해주지 않았을 때 rvRegisterModules = mBinding.rvModuleBeforeRegisterDocList; -> rvRegisterModules = mBinding.rvModuleBeforeRegisterDocList; rvRegisterModules.setLayoutManager(new LinearLayoutManager(getContext()));