September 2020 - last edited September 2020
this is how patches work. mods 'break' because they're made with previous versions of the game. once creators update for the latest patch/version, things will work again.
September 2020
@GothicGyrl and @sevillaab , I have never played The Sims 4 with Mods, so it might be boring for some to not use mods, but it isn't unplayable. Also, it is impossible for EA to know of every single Mod and CC item that exists , as there are thousands! There are thousands now, and that number will keep growing. Mods and CC are 3rd party add-ons which are created around the existing game (not the other way around) and when the game has a change, the mods need to change accordingly. That is just the way Mods work.
And just like @unseenlarks has stated, most Mods creators will make new versions of their Mods that will work in the game again.
September 2020 - last edited September 2020
EA allows the use of mods but they do not support them-- it's up to the mod creators to update their mods and us players to install the updated versions in our game. Mods can be lots of fun and add new game-play but they do require maintenance. Any player who chooses to use mods has to accept that reality. Playing with outdated or broken mods will cause problems in a game or even ruin a game save.
If you aren't quite ready to update your mods after a game patch release you can just play off-line until you are ready. I played off-line for a couple of days just to let everything get sorted out, but all of the mods I use (except for one custom loading screen) were updated on the same day as the patch release.
I use about 40 mods in my game, a couple of big ones and a lot of small ones that do very specific things. It took me less than an hour to look research my mods, download any that required updating, and remove/replace the outdated versions with the new versions. Most of the smaller mods required no updating at all.
There are a few things you can do to make the process easier:
Here are a couple mod tracking sites that I use:
https://forums.thesims.com/en_US/discussion/980785/broken-updated-mods-cc-sw-jb-sept-2020/p1
https://simsonic.weebly.com/modtracker.html
I'm just a regular Sims player, I do not work for EA.