I have several places where invisible walls seem to have generated themselves, and they refuse to be deleted. They look like a dashed line on the plan, and affect the ability to generate other wall types. For example if I try to draw a wall through the invisible wall, it will only draw a wall on one side or the other. I select this hash tag line, open it, and it indicates it is an invisible line, but it won't let me delete it. Any suggestions? Thanks.