Disappearing Lots(Royalty and Legacy)

For some reason my sims lots are disappearing. Some I got from the gallery and the others from my gallery were saved lots of already built lots(being the palaces). And now a lot that I tried building on disappears after entering build mode. I don't know why is happening, but it started two days ago. I'm not using mods, repairing the game, trying to put a new lot or the same lot in the spot that's empty now(which does nothing but lag on and on until I have to go to my task manager and end the sims 4), but I don't know how to fix this problem.