Bubalus causing game crash

I have a family of seven sims; a man, his alien wife and five alien children.

One of the children has a pet Bubalus. I've been playing with this family for quite some time and was playing earlier today when I got the notification that the pet Bubalus had died.

But when I looked at the cage, the creature was still running around.

Hovering over the cage showed no relationship bar whatsoever, not even an empty one, as if there was no animal in there but it was showing the pet's name and it's needs.

Thinking it was bugged, I decided to delete it.

Returning to live mode, my Sims were frozen in place but other animations kept moving such as them bobbing their head to music, music coming out the stereo and the TV still moving. The Sims didn't move, I couldn't switch between Sims and time was frozen. Even going into Build/Buy mode, the music would still come from the speakers and move.

I've restarted the game, restarted Origin, and played with other families in my legacy. Everything else works fine. But whenever I return to this one specific family, and either I delete the Bubalus or it dies (after two days in game), the whole family freezes. I can't save after it dies, delete it, move it to household inventory or anything.

I'm pretty sure it's this specific object that's bugged because until I delete it or it dies, the game for this family works fine.

I have no mods or CC installed.

Any help would be appreciated.