Buildings disappear?

@AriaTheMage

Gonna take a wild guess and ask if you are using any mods?

If so, try the following: 🙂

Resetting the game to factory settings without reinstalling

Many problems can be pinpointed on custom content or corruption in your user data. There's an easy way to reset your game to factory settings without going through the ordeal of reinstalling the whole thing (Path can be different depending on your OS):

• Make a backup of  theSims4 folder in Documents\ElectronicArts to an external drive or a different place on your harddrive (or burn it on a DVD or to a flash drive)
• Rename your theSims4 folder in Documents\ElectronicArts to Sims4_Backup
• Start the game (All your save games will be gone, your options will be reset to factory settings and all your custom content will be gone. Not to worry, it's all still there in that backup folder).
• A new Sims 4 folder will have been recreated in your documents\electronicArts folder. Some folders might be missing for they are only created when you need them.
• You will need to start a new game for the other one is still missing right now.
• See if your error is gone.

The Error is gone now

• Starting putting the folders back, starting with your saves. Check your game after every folder.
• The Tray folder contains all your downloaded houses and Sims that show in your library.
• Only put stuff back from your mods folder that is verified to still work.
• ALL custom content can potentially cause problems. If you found out which folder is causing problems, put your stuff back in groups or one by one until you find the guilty party.
• Not all folders need putting back. See this for what folder does what: User files explained