Help? "Incompatible with Terrain Constraint TerrainTile"

I am having the same problem! Have you found a solution since originally posting this?

@nyamoora No. I've done a few builds since and not had the problem. So it seems whatever it is might be rare thankfully.

I'm having this issue currently too. My lot is completely flat, my house is on foundation, and I was trying to make a new two-story greenhouse that was not on foundation. The issue seems to spawn from that issue for whatever reason. The only work around I could find was to also put my greenhouse on foundation, sadly.

I got this when trying to make a sunken kitchen. I couldn’t solve it, either.

I ran into this when doing my last build. I tried lowering the first floor so my Sim would only need to walk up three steps instead of four to get to the front porch, but I got that error message. I wonder if the step height might have had something to do with it?

I was building my backyard, trimming my pool to make room for a rocket ship and everything was fine. I exit build mode and go to send my sims upstairs to sleep but the stairs disappeared. I thought I accidentally deleted them and when I went to replace them (in the exact same spot) this happened. I hope there is a fix soon because I have been looking for hours.

Hello
You may like to post feedback on the Build Mode feedback thread.
https://forums.thesims.com/en_US/discussion/787346/build-mode-feedback-for-ea-now-testing-the-11-13-18-patch#latest
Or the AHQ EA site
https://answers.ea.com/t5/The-Sims-4/ct-p/the-sims-4-en

"cronychie;c-16862300" wrote:
Just build a tiny portion of a foundation and set up your stairs, you can destroy the foundation piece using the hammer tool after constructing the stairs.

Not a fix, but it's still a solution

Does that work indoors?

I think it might have to do with the level of the terrain between the top and bottom heights of the stairs you're trying to place. I've had problems with this when I've adjusted one or both ends of the terrain levels - it may be that you've flattened the lot but not exactly to height 0? Or the height your foundation at is between acceptable height slots?

"cronychie;c-16866603" wrote:
> @GalacticGal said:
> cronychie wrote: »
>
> Just build a tiny portion of a foundation and set up your stairs, you can destroy the foundation piece using the hammer tool after constructing the stairs.
>
> Not a fix, but it's still a solution
>
>
>
>
> Does that work indoors?

I haven't gotten this issue indoors yet, so i don't know :'( Maybe you could try deleting few blocks of floor there and add the foundation to install the stairs, then replace the foundation with the floors again?

That's interesting. I do wonder if that would work?