Missing another foal

I'm missing another foal.
I bred this mare Button (#533980) to this stallion Williams [D] 62.75 f b (#282585) 5 days ago. Both say "last bred 5 days ago". Up to yesterday it still said on her page "She will give birth tomorrow",
mare says she has 4 foals bred, but only 3 are listed when I click on it. So everything seems to be right, but the foal is nowhere to be found.

I've progressed every day, mare nor stallion have been in a locked division. What's going on here?

Locked as Duplicate topic see This topic for more information. Thank you!