@dd03979
@puzzlezaddict asked me to take a look at this post so here I am. Tbh, I've no clue what might have happened to cause the entire building to disappear. It does make sense that the apartment would go missing if the underlying building went missing. There have been several posts here where apartments became misaligned with the building they were in but not one where either building or apartment just disappeared altogether. I mention that as it could be related. So, a couple of questions,
Do you play with mods? If you do, then do you have any that can alter the world outside of a lot or apartment like TOOL? If you do, then did you alter or try to alter anything in the world in that zone before the building disappeared? And do you use MCCC?
Do you have an LE, or did you get one before you noticed the problem? If you did, could you attach it to your next replay. If you use MCCC, do you have an MCLE? If you do, attach that file as well. There might be something in one of those files that will give us a clue to what happened.
Since the building is there in a new save, then at least the problem is just in that particular save, so it would appear that there is nothing wrong with the game itself which is good. A reinstall or repair won't do any good since either of those only affect the game files, not saves. And I hate to say this, but I really doubt you will be able to get the building, apartment and sims back in that save because I think the save is probably corrupted and you'll have to abandon it as I know of no way to get the building and apartment back. TOOL might do it, but I suspect that it won't since the building is more or less hard coded in the world and since the apartment rests on the building........ I don't even know if you can find that building in the build debug items, but you can look. It might be there and you can try. Regardless, it will be a lot of work and take a lot of time to fix if it can be fixed. The sims might be able to be rescued if you can get to them in Manage Households but I don't know for sure.
You can try recovering an earlier version of the save through the Load Menu so you can get the sims, building and apartment back but if you saved more than 5 times after the problem showed up, then you might not be able to. You'll just have to look and see. But that won't necessarily stop it from happening again. It might but might not too. All you can do is try to see if it does happen again. If you have the LE files, that might give a clue.
If it does happen again in the recovered save, I think the best thing you can do if it does happen again is to abandon the save and save all of your customized lots and all your sims to your Library, then start a new game and place the lots and sims in the new save and start over. You'll lose a lot. All the relationships outside of each household being the biggest and all the unlocks you've unlocked. You can save almost all the collectibles by placing them on the floor or a wall before you save the lot. Same with other things like the career reward objects. But sims will retain all their skills and traits at least. If you need help with any of that, just ask and either I or @puzzlezaddict can help you with more specific directions if you need them.
Sorry that the news isn't probably what you were looking for.
Hope this helps.
