A build mode error??

@Yonna02 Hmmm... we could start with questions, clarifications, and a few things to try...

• When you get the error, what exactly are you trying to do? (Beginning to drawing out a basement room, extend one, etc.)
• Can you please include a screenshot of the area and of the error. 
• It sounds to me like the wording of the error indicates that something will be deleted if you add this area/do this action... something that cannot be deleted or moved to your household inventory. Is there any item that is stuck or residing in the area already that you can see?
• Is this a lot you made or from the gallery? Can you please share the lot so I could test in my game? ( Click spoiler tag for directions... )
  
  Spoiler

  You could name it something like "Basement Error Test". Then please add a comment in this thread to let me know the name, and please let me know if your User ID in the gallery is different than it is here in the forum.
• Does the lot have any CC?
• Do you have Mods/CC in your game (or did you previously)?
• Did you use any items from debug?
• Did you use MOO or alt placement to place items in ways that are not default placement/snap placements? 
• Did you enlarge items with MOO? (Via the  [ ] keys)
• Do you have MOO when the error occurs? When MOO is active many items do not delete in the normal manner.
• Some debug items will not delete or move to inventory via 'delete' and you have to grab them with the hand/select tool, which opens an area at the bottom left of the screen, then you can drag the item to 'sell' it for $0. For certain debug items this is the only way to delete them.

I look forward to your answers and helping you track down the issue. Thanks!

@Yonna02  There are objects generated on a lot with the Haunted House lot assignment, that can not be picked up in Build mode, only 'destroyed' in live gameplay by kicking it etc. Send your sim to look for any hands sticking up from the ground, or thorny plants, and click on anything. If the interaction says destroy, do that. Then try to make a basement again.

Oh, and little dolls and various puddles as well. 

It worked! There was a cursed symbol on the floor that I didn’t notice before, after I cleaned it up i was able to make my basement. Thank you!