[NEEDS INPUT] Basement Split Level Rooms: Irremovable Basement Floor (1.66)

@milliemcintyre 

Ok.  That's interesting.  I'll take another look and see if I can replicate what you did and see what I get tomorrow.  You might be right about the game and how it recognizes rooms.  Makes sense to me anyway.  Build mode can be weird at times in what it lets you do.

Another thing I thought might be connected is cc.  When I loaded your save, the first time I entered the lot it said that it removed 672 build items and substituted 31 more.  That's a lot of cc on that lot and cc can cause problems even after it is removed as it sometimes leaves a stray bit of data attached to a lot or in a save.  I know you said you tried it in a vanilla save without any cc, but did you leave any build related mods in like T.O.O.L. or something else?  Could be something like that is interfering somehow.  Just a wild guess though and probably not since it did happen in a vanilla game for me without any mods or cc in but you never know.  Doesn't hurt to consider it anyway. 

Another thing you might try is deleting the localthumbcache.package file if you haven't done that yet.  That sometimes clears up problems, especially when you have a lot of cc and take it in and out of the game.  The game will generate a new one so it doesn't hurt anything.

Hope this helps.

Edit:  Ok.  I took another look at this today and was able to reproduce the issue.  But I did it a different way than you did.  But ended up with a dirt floor that could not be removed short of deleting the entire build and starting over.

I went to the same smaller lot in my test save as you did in yours and built a 2 level basement then deleted the floor in between and added rooms in the lower level.  One against the wall and one in the center of the floor.  I deleted the floor of the upper level and the ceiling of the lower room.  Then added rooms right above the lower rooms below.  Not a problem and I didn't get the dirt.  Then I added floor tile back to the upper level.  Since you can't tile a space that way, to get a floor so I could tile, I had to add the ceiling back in the room below, then place floor tiles on the upper level.  The usual concrete floor showed up and I tiled over it.  Then I deleted the floor and the dirt showed up.  After that, I could not get rid of the dirt no matter what I did.  Adding and deleting floors and ceilings again did nothing and the dirt floor remained.  So there is definitely something now quite right about how it works.  But it does seem that the order in which you do things does matter as I could get the 2 story space at first. It was when I put the floor back via adding the ceiling below was when it showed up.

Hope this helps.