Content not installed error

I have had this issue twice, the first time was around December last year and the other, today. I had a message that said that some of my build mode and create a sim content was not found in the game because it was not installed, I don’t use mods and the first time I didn’t find anything missing that I remember, but today I found one of the formal dresses was changed and I can’t remember which one I chose for the sim. Also, the first one happened when I started the game and this one when I came back from my vet clinic. Please, let me know what happened and if I need to uninstall it or something.