My sim disappeared after coming back from a free vacation

For anyone still experiencing this glitch, here’s how I fixed it:

First you want to go into Edit Town and click on merge household. Then you place a sim from another household into your one and all your Sims will return from the vacation immediately when you click Return to Game. You’ll unfortunately lose everything in the Sim’s inventory, however it’s better than losing the sim outright.

Hope this helped 🙂