Can you press the hidden sim in the left corner where the household will be (The portrait panels)? If not, go to the paragraph below. If so, press the hidden sim on the panels. Then, press Ctrl + Shift + C on your keyboard buttons at the same time, and then release the buttons. If a bar has appeared at the top of the screen, type without the quotation marks "testingcheatsenabled true", and then press enter. Hold in the shift key and left click on the ground. Make sure it's the ground or a floor, NOT a rug, or an object. Then press teleport here when the options are displayed. If this does not help, then go to the next tip below.
Some sims can get glitchy. To fix this, press Ctrl + Shift + C on your keyboard at the same time, and then release the buttons. If a bar has appeared at the top of the screen, type without the quotation marks and replacing FirstName with the hidden sims first name and, and LastName with the last name of the sim, "resetsim FirstName LastName".
This is all I know. Have this happened to you before? Please comment and tell me results and answers. Thank you.