Can't load into build/buy from live mode, and messed up when from worlds

[rvrazors]

Product: The Sims 4
Platform: PC
Which language are you playing the game in? English
How often does the bug occur? Every time (100%)
What is your current game version number? 1.62.67.1020
What expansions, game packs, and stuff packs do you have installed? All expansions and game packs, most stuff packs except My First Pet and another two or three I can't remember
Steps: How can we find the bug ourselves? Place a prebuilt lot. I can't tell if this happens in just Newcrest or globally, but because I mostly play in Newcrest this is where I know for sure it happens. Move a family into it, try to enter build mode from there. Build mode glitches out and will not open. From there, return to world selection and open the lot into build mode from the neighborhood screen, where you will encounter the "place room" mode and the Signature Queen Anne Living Room with no preview, priced at 999,999,999 and immovable, covering half of the build screen. It can still be built around, and the menu mostly works- I can still enter build and buy, it's just half-blocked (and since all I needed to do when I last encountered it was replace a wall dressing, it was annoying but not impossible). It cannot be removed, and the buy button does nothing.  It returns unless you restart the game entirely and return to build mode WITHOUT entering live mode first.
What do you expect to see? Normal build mode without an impossible-to-remove overlay.
Have you installed any customization with the game, e.g. Custom Content or Mods? Yes, usually, but it happens with or without mods. I removed them and it still happened. The screenshot is taken with half of them removed, but it happens on the other half, too.
Did this issue appear after a specific patch or change you made to your system? No. 

[jpkarlsen]

@rvrazors 

Move your Mods folder to the Desktop and delete localthumbcache.package. Then test the game.

If it works now check for updates to your Mods and CC. Add it back a little at a time while testing until you have found all that are broken.

[rvrazors]

Still doing it without mods and thumbcache and across saves.

[jpkarlsen]

@rvrazors 

Please test if you have the issue in a new game without Mods.

[rvrazors]

New game no mods, still does it. I placed a (base game built) home from build mode, exited, created a family of 5 (4 randomized sims and a cat) to put in it to sort of mirror my initial conditions, loaded into live mode, attempted to open build, couldn't, went back to build from the world menu, and once more encountered the immovable living room thing.

I just tried repairing my game, but still, same thing.