In the new 18w47a Snapshot, my world from the Snapshot 18w46a first loaded correctly. But then, after I had died and respawned, it did not load anything else except the one chunk I spawned in. I had a set spawnpoint. It was raining and the rain worked properly in some areas, but in others I couldn't use my Riptide 3 Trident, even though it was raining.