Please use this thread going forward: Save Game Corruption (Disappearing Lots/Error 800 or 801) | EA Forums - 5037272
I don't think that's it, I was searching on Google and there is something interesting in the developers' notes that I suppose has to do with the error.
Attached image.
I think that after the expansion the game was imposed a limit on residential lots per saved game. Which if so, I see it as very poor, because counting all the available worlds that we have to build, the developers are forcing you to not be able to have residences in all the available lots on each map, since if you count there are more than 99 lots available to build in the game, and if you remove some lots such as parks, bars, pubs, etc., you still have much more than 99 available.
So of course the multifamily lots are several lots in one, so I suppose that When you exceed the limit, the game corrupts batches created from other maps so as not to exceed your limit. Maybe this is what is hurting everyone, since I have seen gameplays of several YouTubers who also have this error in their games.
Either the developers eliminate that figure or increase it to a greater amount as they have for the limit of active families or some MOD creator that allows that figure to be varied or increased.
These are my assumptions about this.
Just been giving this some more thought and don't think that's the issue as TwistedMexi has a mod to increase the unit limit to 250 units. I've tried using this mod and still have the same issue.
I'm running out of ideas, even so I'm doing tests with my daughter's saved game because I can't find a cause for this error, since it's not something new, this has been happening for a long time, only now with the release of the expansion It has increased much more, it even happened to James Turner in the middle of a game on Twitch, and the same to other YouTubers, this is something common and EA has moved on from this along with other problems that have been going on for years.
Have you tried repairing the game? If so, did it help at all?
If I did it and nothing, the luck is that I have created backups of all the games on the PC, both mine and my daughter's, to avoid all these things. For now, I suppose you have to continue dragging the error as far as you can, because something tells me that at a certain point the game will end up prohibiting you from accessing all those broken lots. I also told my daughter to play but without building any new multi-family lots, it's unfortunate but it's the only thing I can think of or to start a new game from scratch but she doesn't want to leave her old game. So let's wait and see if EA decides to solve this once and for all.
