What gameplay feature is this bug affecting?
my lions

What's the issue? Please include any error messages you receive and as much detail as possible.
i'm not sure if this is the correct place to report this, but this has almost made me want to quit. a few days ago one of the lioness i got had a mutie cub, the first mutation i've ever bred. this cub was quite special to me, and it was also a pretty good cub. after the cub got weaned off its mother, it just suddenly died for no reason and i got no notification from it. i fed it and played with it, but it still died. i didn't trade it. i cannot be online all day everyday, so seeing my cub die for no reason really makes me mad. i'm not sure if anything can be done, but i wanted to report this since it's really making me upset.

Any links relating to this bug? For example, if a particular lion is bugging, what is the link to that lion?
none.

Any screenshots you can provide us with?
i don't have any proof, i only had a picture of the cub but i recently lost it from deleting all of my pictures.

Please provide us with step by step explanation how this bug happened so we can attempt to replicate it. If it's complex, please include screenshots where possible:
i can't really explain it since i don't even understand why it happened, or how it happened.