[ARCHIVED] Orange/Green Exclamation signs over lots / Houses disappear

It was the same for me.

I tried to create new saves with my sims and lots from the save that is broken (saved them to the gallery and placed them in a new save).

But the problem came back every time. 

I was able to create a savefile that is near breaking (1-3 households more and it breaks) and if i deleted a lot or household i was able to place more. (Only in the game, deleting households or lots in the gallery dodnt change anything for me) 

At the moment i am at save try number 4. 

And i was able to place every lot i wanted and every household. No exclamination mark anywhere until now. But it was a lot of work. 

I have read a lot about what can cause problems here and on reddit to be as safe as possible. 

As an example, before i placed the lots in my new save i also placed them in a different (testing) new save. 

I only placed them in build mode. Never from World fiew and then left build mode, enter the lot again and leave it again to see if the game will crash or not. If not i marked it as safe and placed it in my new save file. I was able to found out that a few lots i had from other people from the gallery where broken (one was a San myshuno appartement from the gallery) what i didnt realised when placing them first time. I also dont know if this could trigger the bug. None of these builds where the one where the spreading exclamination mark bug first appeared. Thats always the second lot in willow creek in my saves. No matter if its a Park or a redidental or the original EA lot not Visited once. 

Also a weird thing that happend, in try number 3 i visited this lot that breaks first (willow creek lot 2) in build mode after every household or lot i placed. 

Shortly before the bug starts the game started to say there are Objects missing because i dont own the Pack or something (even if i visited it before 10 Times witjout problems) (i also have every Pack) and some Objects where indeed missing. After placing more household and visiting again the building became empthy. (Walls still there but no objects) More placing and the lot will become completly empty and loose its lots type in my game.

Does anyone else have a savefile shortly before the orange exclamination mark appeares and can/ wants to check if its the same order of events in their game ? 

I followed so many steps and rules but i have no idea if any of them is the reason the Bug did not occur in my newest save yet. I still have a lot to do. I dont have recreated Clubs, Animals and friendships yet and the game hasnt created a lot of NPC until now so i will write here again if eighter the bug comes back or the save is finished to tell you which rules i followed. 

I hope you all have a good weekend and thank you for the help and Informations.