Every animal and villager (named included) disappeared

Loaded world to find every single animal (named included) and villager had disappeared from village. All up two named animals disappeared (including horse with saddle), about 20 animals, iron goldm and 20 villagers.

 

No option to load old save, unable to craft items that have disappeared... all up about 20 hours of work disappeared and young daughter is devastated. 

 

Not particularly hard to implement a backup sudden that would stop this happening I would think. If I could go back half an hour game time rather than redo 20 hours instead, I would.