When updating from 19w07a to 19w08a or 19w08b, every villager and iron golem in my village will vanish except for two. It's not the same two every time, but always two will be left. Sometimes if I reload a backup and try again the missing villagers will be visible for a split second as the world loads but then they will disappear.

The missing villagers can't be interacted with or hit, they're not there. Reloading the world has brought them back on one occasion, but they disappeared again later upon closing and reopening the game.