This is not a fix, you cannot fix the corrupt save, but you can prevent it by making lots of manual seperate saves and saving stuff to your library alot to prevent future cripling losses of your game if it would happen again!
UPDATE: i managed to recover from a save from 3 days ago, but it seems that once you have that one buggy save file active, it ruins it for all the others, Restart your game if you need to find wich save game still works instead of going back to the menu to select another one. Please link this thread to all the other builders and players you know so they know how to arm themselves against this crippling save error!
You can find your saves folder under documents, electronic arts and then under saves.
Tip: This will only work if you save everything manually on seperate files, if you only used autosave you will have to start a new game or pray you have a very old uncorrupted save file somewhere in that folder!
step 1: Allways save all your houses in seperate saves, maybe even different stages. I would also suggest to save your house to your library every time you close as an extra safety measure!
step 2: Copy the save folder of your sims 4 and place it on your desktop so you have acces to it. After that, delete all the save files from the save folder in your actual sims 4 save folder! do not remove the 2 folders in it though, only the .sav files!
step 3: Now your save folder should only have the 2 folders in it ( scratch and SerialGUID ) but no actual savegames. What you do now is important, Check the dates wich the files were last modified (you can organise your files via name, date and most modified in your explorer screen) . when you copy over your save files to your clean save folder again, make sure your autosaves, the 00001.saves or/and the latest manual save, wichever save corrupted your game is NOT in the folder. If it was your latest manual save, remove the autosave as well! This is to prevent that save file from loading and corrupt your game again.
Step 4: Start the game, and instead of clicking the play button, look on the top right and click on the little square floppy disc that sais load game and select the save game that you had before the save file you made that made your game go corrupt, in my case that was a file i made the 17th of may, i deleted the one that said the 19th of may (date last modified dates)
Your game should be loading correctly now and you should be able to go in to your houses and sims familys without it returning you to your map screen!
Keep doing these steps and go down the list of save files untill you found a save file that is not corrupted.
I hope this tutorial thing helped a bit!
IF YOU HAVE THIS SAVE ERROR THERE IS NO WAY YOU CAN RECOVER THE THINGS YOU HAD IN YOUR SAVE FILE UNLESS YOU SAVE EVERY HOUSE TO THE LIBRARY AFTER SAVING A BUILD!
i hope this tutorial thing helped a bit. But it does seem that once you load your buggy save file, none of your save files work correctly anymore.
It all happened a month ago, i tried to load in to a house of a savegame, but i could not! it just refused to load and brought me back to my
map select screen! I looked for a save that did load and that one was from 2 months ago back then so I lost alot of progress then.
Since then i saved ALL my projects in seperate save saves, not autosave, no each build had one save. Now today, i want to start streaming again, and guess what? None of my houses want to load, they return me to my map selection screen each time. Even my families, so i thought, ok, lets load the file that i used 3 days ago. see if that works, guess what? It did the exact same thing. For some reason, even the save games from 3 days ago do not want to function anymore and i might have lost my entire neighboorhood this time! Is there a way to fix this save game so i dont loose all my data again, or am I loosing my stuff forever again?... Since this is the second time this happened, did someone else have this issue and how did you fix it? I am now reinstalling my entire sims game from scratch in the hope this will fix the save games, but i fear it will not!