Re: For Rent: Sims can't get into their own apartments & other things!

So I had the same issue and I figured out what it was. You have to make sure any space that is for everyone is marked shared. So for example I built a duplex and the front space in front of the 2 doors was marked for one of the units (not the one I was playing) instead of marked shared. So just click on the space and choose shared. That should allow you access the unit!