I previously made a report about excessive breeding amongst villagers. In that report, I mentioned how 62 villagers somehow became 149, but I couldn't figure out how enough disappeared that any of the 51 beds was unclaimed. Well, now I think I know why.
Today I farmed my crops, which are located in fields close to my main village, close enough they the village could render, depending upon where I was standing. After going through all of the effort to farm 3072 wheat crops, 3072 collective carrot/potato/beetroot crops, 16 stacks of sugarcane, and many stacks of pumpkins and melons, I was about to go start trading. But then my game crashed.
I have several saves of this world now, so I know there should be 62 villagers. But when I revisited my village after the crash, I found 29 villagers, so 33 apparently despawned, more than half the population.
I've had several other crashes that I thought might be mob-related, where mobs get deleted because of the crash. In this case, however, I think there is strong evidence that loading/unloading the villagers a certain number of times may have caused the crash, since I would have been rendering the village repeatedly as I harvested my crops.