Someone else may have a better solution but if it was me this was happening to I would move out all families so the apartment is not occupied, then change the lot zoning to residential, save & exit to neighborhood, go back in, replace the offending items, change the lot zoning back to apartments, save & exit to neighborhood, go back in, save & go back out, move the Sims back into the problem apartment & make sure it works ok. It probably took longer for me to type this than it would to do what I typed.
