@MelanieScribbles I personally would not trust that save, because the lot is corrupted and in my game the corrupted lot kept throwing errors until the save became unplayable. Besides some general wonkiness, the thing that convinced me my save was corrupted was when I paused the game and the regular resume button no longer worked. I had to hit pause twice to resume playing. From there it just got worse and became unplayable. So if that happens to you, the save is toast.
Thank you for adding what you did to try to get the lot to work. I have tried several things as well, which I enumerated earlier in this thread. One thing we all have in common is not being able to find a solution. This is a really bad situation, and I fully expect more and more people will run into it. For me it was a game breaker.
If you want to try to keep the save, then my advice would be to place a Residential Rental build on that lot, and then leave it that way. Don't play it, but get the game to recognize it as a genuine Residential Rental Lot. The reason I advise that course of action is because most of the errors thrown in my game were about the rental manager not being able to find what it needed to locate, if the lot was in some state other than fully Residential Rental. So it may help to let the rental manager find what it is looking for, while we wait for EA to fix this untenable situation. No guarantees, but that is my best bet.