After an update to the Natural Texture Pack today, the texture pack no longer works on Realms worlds. I have tried deleting and reinstalling the pack, deleting and reinstalling the entire game, or just removing the pack, loading the world, and then re-adding the pack and loading in again. None of these have fixed the pack on my Realms world.

I tested the pack in a non-Realms world and everything loads fine. I have tested this bug on the Windows 10 and Nintendo Switch versions of the game with the same results.