Sims can’t resume already started knitting projects
The original bug was fixed but there's still a few reports from people not being able to resume knitting projects.
Grab your yarn and knitting needles — in The Sims™ 4 Nifty Knitting Stuff Pack, Sims can craft their own clothes, toys, and knittable home décor! Young and old Sims alike can take a seat in their new rocking chair and start creating. When you’re done, rock your handcrafted styles or sell them on the new online shopping platform, Plopsy.