Interesting, I copied the build to the library and then bulldozed the lot and replaced it and that was no help, so then I went back to the empty lot where I had the successful test earlier and tried again there but this time I was getting the same error as on my build lot.
Solving this is important to me not for the sake of my current build but so we can spread the info about the cause and a fix or work around once found so that all builders can have stairs going right through the foundation with out requiring a landing at foundation level.
Ironically it's because building in Sims3 is so challenging that I enjoy it so much. I beating little challenges like this and bending the games stupid rules to my will.
Okay, next thing I did was turn off all cheats (assuming that maybe one or more of the cheats like moveObjects, constrainFloorElevation or testingcheatsenabled might be interfering) and then picked another empty lot for a test and was able to shift click stars through the foundation.
Then I went back to the first empty lot that I got a successful test on and tried again there with all the cheats turned off and suddenly I got the same error as on my build lot, even though I go to edit town mode and bulldoze the entire lot after each test (which should restore it to it's original state as an empty lot) so it seems that once this glitch happens it some how corrupts that lot permanently. Still no closer to finding the cause yet though.
Quitting and restarting the game didn't help. The corrupted lots remain corrupted.
hmmm, bulldozing the lot while moveObjects was on seems to have corrupted a lot.
After trying all sorts of tests trying to think of a way to un-glitch my lot I gave up and restarted the game and opened a new game file to start over from scratch on a fresh lot.
The first thing I did was drag at a quick foundation of unspecified size just kind of randomly, then threw a basement under it and shift-clicked some stairs in to make sure that was working and it was.
Then I just hit undo a few times to start over with the foundation the exact size and shape of what I had already built. I had no cheats on while doing that.
Then when I went to shift click the stairs into the basement they wouldn't go. I was getting the same old "Modular stairs have no steps" error. This is a 40x40 lot with a 20x20 foundation starting 10 tiles away from the street and 5 tiles away from the left side. A 20x20 foundation with absolutely nothing on it and a 20x20 basement underneath.
Couldn't put stairs anywhere in that foundation. So I hit undo again getting rid of the foundation and basement and again just dragged out a quick foundation of random size and location and matching basement underneath and low and behold shift clicking the stairs worked again.
So I hit undo again and went back to the foundation and basement the desired size and location and again the shift clicking of the stairs stopped working again.
So by now I'm concluding that regardless of how far away from any walls you're trying to put your stairs, Shift-clicking stairs just doesn't like certain foundation sizes or certain basement sizes so I hit undo yet again and dragged out another randomly sized foundation and basement and shift clicked in the stairs at the precise location I want them at in relation to the edges of the lot and the once the stairs were in resized the basement and foundation to what I wanted around the stairs.
So then I thought, Maybe I can go back to what I've already built and just add some foundation and basement to make it no longer a perfect square but a bit more random, just change the size enough to get it to let me put the stairs in and then delete the extra so I wouldn't have to start all over again but no such luck. No matter how much basement and foundation I added I couldn't get it to let me put the stairs in so It looks like I am going to have to start over on the lot where I did manage to get the stairs in.
This is just crazy. It works but only when it wants to.
