Bug/Issue Invisible Animals

Overnight, in-game, all of my animals have vanished. They weren't killed, and they're nowhere on the farm -- the gates are always kept closed. We had five or six chickens, two ducks (and also two ducklings that hatched after the first disappearances that have since also vanished), and four cows all go missing. I've tried buying more animals, but it says the barn/coop is full, and I can't demolish them. Does anyone know of any way to unvanish the animals and/or bypass some rules to remove the structures with the animals still 'in' them?

 

I don't know if this will work but try to construct a new barn/coop and see if you can replace the animals to the new one.
Also, you can try to sell your animals or let the doors open and go sleep early.

 

I can't sell or move the animals because they're completely invisible. They don't eat, the chickens and ducks don't lay eggs, and they don't make noises - But, when trying to delete the barn/coop it says they still exist and live there.

I've tried moving the buildings, leaving the gates open, leaving the gates closed, upgrading the buildings, etc... No luck.

 

@SilverKytten Can you post a zip of your save files?