Issue: You can't use your D-Pad to raise and lower walls, move floors, or switch sims.
Simply closing your game out completely and restarting will fix the issue.
Solution: Delete your Userdata file in your saves folder. Do not Delete Save Files, only the Userdata File! Reboot your system afterwards.
PS4 Users Please share your affected save files with QA as requested here: Share your Saves
PlayStation:
Go to Settings > Application Saved Data Management > Saved Data in System Storage > Delete.
Select the Sims 4.
Set the check mark beside the userdata file.
Select Delete > then OK to confirm your decision.
Restart your console.
XBox:
XBox does not store it's game user settings in the game saves folder. Like everything else, these files and settings are cloud based. The user settings file is what needs to be reset.
Another poster had said they had luck enabling free cam from the top right of their screen to lower walls in Live mode. Enable Free Cam
You can also try loading a save from before the issue started to see if that helps.
You can try deleting the "reserved Space." Several XBox users have reported this helps them.
On Home, select My games & apps.
Highlight the Sims 4, press the Menu button on your controller, then select Manage game & add-ons.
Select Saved data
Select Reserved Space and select Clear Reserved Space
Restart your console by pressing and holding the Xbox button on the front of the console until it turns off, wait 30 seconds and launch TS4 again.