lillieleeds Does this happen with a new save too? If so, please provide a dxdiag. Hit Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop. From there, you can attach it to a reply using the paper clip (Attachment) icon included with the other formatting buttons.
If a new save is fine, please open Documents > Electronic Arts > The Sims 4 and delete any lastexception files you find. Try again to load one of your affected households, and when it doesn't work, close the game and see whether there's a new LE. If there is, open it and delete the first line, then attach it to a reply here.