My Sims can’t sit down on anything except beds, help!

@cmlhmj6c3d7e I've never seen this issue not be related to outdated mods or custom content. You could test without the Mods folder, but I'd suggest first doing a batch fix of chairs with Sims 4 Studio.

If that doesn't fix it, drag the whole Mods folder to the desktop and delete localthumbcache. I also suggest making a copy of your Saves folder, just in case you forget to exit without saving. You can then confirm that it was mods/CC and start batch testing to isolate the cause.