This problem occurs after corruption of household data or setting of invalid travel states by mods. You should exit the game without saving when this occurs and if you've already saved then you'll have to roll back to an earlier save.
The Sims 4 automatically stores up to five previous versions of each save slot. Check the contents of your save directory under "My Documents\Electronic Arts\The Sims 4\Saves" and locate the current slot, for example Slot_00000008.save. If your current save is Slot_00000008 then you'll see the automatically generated backups as Slot_00000008.save.ver0, ver1, ver2, ver3, ver4, and ver5. These backups are in order from newest to oldest therefore you can restore your previous save by removing Slot_00000008.save and renaming Slot_00000008.save.ver0 to Slot_00000008.save. If the same problem occurs you can repeat this process with ver1 - ver5 until the you're able to load your household.
Remove all mods which affect residential lot placement or travel destinations before saving your game again. You do not need to create a new save or remove households.
