Can't knit rugs in nifty knitting pack?

@emmawieder , can you direct them to knit other things?  Can you have them sit down first and then try to knit a rug?  Is it just with one Sim or with more than one.  Have you tried it with Sims in a different Save Game file (in case the other save file has a glitch)?

If it is just in that one save game file and in the one household, you can try to travel with your Sims that are affected with this to another lot like a park, gym, or museum, and then travel back.  This will sometimes fix glitches for those Sims or that lot. (You can try to move out and either move to a new place or else back into the original house, but this is more tedious and I would only try it after trying everything else.)

Finally, do you use any Mods or Custom Content (CC)? If you do, then that might cause problems when CC/Mods get outdated, which usually happens after a game patch. 
If you have any Mods or CC you can try all of the following in order:

1) Move the Mods Folder to your desktop

2) Delete the  localthumbcache.package file in the game folder. (This is very important!) 🤨

3) Fix you game in Origin by logging in and go to Library, then right-click on The Sims 4 and choose the "Repair Game" option from the list.  Wait until Origin finishes repairing all your packs and not just the base game. (If you are on a Mac it will only repair the base game). Do not add your Mods folder back yet. 

4) Now, when you turn on your game again, it will create a new mods folder that will be empty.  Check to see if your game is now working without mods/CC.

5) Now you can try adding back items from your Mods folder one at a time checking your game each time to see which item is causing your game to not work properly.  If you have a lot of items, you can try the 50/50 Method, testing in batches. When you have deleted all the outdated Mods/CC you can add your Mods folder back to your game (and hopefully you will have updated versions of the Mods and CC items to take their place!)🙂

The CC creators will usually update the CC items and Mods after these updates, so when you find out which one is the culprit, you can get the updated version from whoever made that item of CC in the first place.  You should try these steps anytime you have problems in your game to rule out CC/Mods problems.  It is the responsibility of the Mods/CC creators to update their items anytime EA releases a patch/update, and it is the responsibility of the people who use Mods/CC to make sure they are using the most recent version, which in your case was September 3rd. 

Please update us on your situation! 😇