Corrupt World in one save file

I’ve got this save file that I’ve been playing for years. I tried to add a residential rental lot into San Sequoia and as soon as I did it the world turned white and I can no longer access it. I’ve gone onto an older save file and discovered that the world is still accessible just not in my main save file. I know that For Rent is super bugged but I honestly haven’t had any problems until now. I don’t know how to un-corrupt San Sequoia?

info about my game: I play on steam deck via steam, I use to play via origin but transferred over to steam. So I can play the packs I bought on origin but steam doesn’t recognise that I’ve bought them and still says in the steam store that I don’t own them.

* I have no mods or CC