Missing sims bug

After over 200 hours into MySims, I've also run into the disappearing sims bug. Several townies and commercial sims are missing and never show up when I enter their homes. Other sims don't visit them either so all the restaurants etc. are empty. 

I've seen several people mention this bug on the MySims subreddit so it appears to be quite common with people who have put a lot of time into their games. I really hope it can be fixed.