No adapter attached; skipping layout

In my case this problem occurs because there was a view on my layout which moved my list container and it was displayed too small

You didn't attach the adapter because you create it after you try to attach it:

mRecyclerView.setAdapter(mAdapter); // Here, mAdapter is null
mAdapter = new CountryAdapter(CountryManager.getInstance().getCountries(), R.layout.card_layout, getActivity());